taxonID	type	description	language	source
03F2686FFF97925942EBFBA3FC15909D.taxon	diagnosis	Valvae lineares ad lineares-lanceolatae marginibus leviter convexis, apicibus aliquando subrostratis. In speciminibus minoribus, apices paene non protracti. Longitudo 15 – 22 µm, latitudo 2.8 – 3.7 µm. Area axialis angusta, linearis, non dilatans in aream centralem. Area centralis formans fasciam rectangularem, potius latam. Raphe filiformis, ramis rectis. Terminationibus raphis proximales extensae solum leviter supra strias centrales cum poris parvis, distantibus inter se. Fissurae raphis distales non discernandae in microscopio photonico, probabiliter falcatae. Striae parallelae ad leviter radiatae in media parte valvae, moderate convergentes ad apices, 16 – 18 in 10 µm. Lineae speciosae longitudinales non aspectabiles in microscopo photonico.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF97925942EBFBA3FC15909D.taxon	description	Valves linear to narrowly linear-lanceolate with weakly convex margins and usually subrostrate apices. Smaller valves with almost non-protracted apices. Valve dimensions (n = 28): length 15 – 22 µm, width 2.8 – 3.7 µm. Axial area narrow, linear, not widened towards the central area. Central area forming a rather large rectangular fascia. Raphe straight, proximal raphe endings extending only slightly beyond the last central striae. Raphe pores small and distant. Distal raphe fissures indistinct, probably sickle-shaped. Striae parallel to weakly radiate in the middle, moderately convergent towards the ends, 16 – 18 in 10 µm. Longitudinal lines not visible in LM.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF97925942EBFBA3FC15909D.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 068, leg. B. Van de Vijver, coll. date 18 / 01 / 2009, slide no. BR- 4251 (holotype BR), slide PLP- 196 (isotype University of Antwerp, Belgium), slide ZU 8 / 25 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF97925942EBFBA3FC15909D.taxon	biology_ecology	Habitat: — The type population of P. pseudolaucensis was sampled from the sandy bottom of a small pool near the southern beaches, with an almost circumneutral pH (7.2) and a low specific conductance (<100 µS / cm) value.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF97925942EBFBA3FC15909D.taxon	etymology	Etymology: — The specific epithet refers to the close resemblance to P. laucensis Lange-Bert., Rumrich & Krammer (in Rumrich et al. 2000: 200).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF97925942EBFBA3FC15909D.taxon	discussion	Observations: — The type population of P. pseudolaucensis has a comparable valve outline and dimensions as the type of P. laucensis although the valves are somewhat narrower (width 2.8 – 3.7 vs 3.3 – 4.0 µm in the type popultion), have a higher stria density (16 - 18 vs 11 – 14 striae in 10 µm in P. laucensis) and a much smaller central area with the proximal raphe endings extending only slightly beyond the last striae. Pinnularia altiplanenis Lange-Bert., Krammer & Rumrich (in Rumrich et al. 2000: 197) differs in having a larger valve width (3.5 – 4.5 µm vs. 2.8 – 3.7 µm), as well as more radiate striae and a larger central area. Furthermore, the latter can also be separated based on its more linear outline with parallel margins. Pinnularia pseudolaucensis also resembles P. amaniana (Krammer 2000: 121) Kulikovskiy, Lange-Bert. & Metzeltin (2010: 364) but the latter is wider (4.7 – 6.1 µ m) with a wide axial area (Krammer 2000). Pinnularia schoenfelderi Krammer (1992: 70) is much larger (width 5 – 7 µm) (Krammer 2000). Other small-celled Pinnularia species such as P. bertrandii Krammer (2000: 122) and P. perirrorata Krammer (2000: 41) differ sufficiently in valve outline and axial area to exclude all conspecificity.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF90925842EBF8F0FDA39297.taxon	diagnosis	Valvae anguste lanceolatae, margines leviter convexae in media parte valvae, graduatim decrescentes in apices capitatos, anguste rotundatos. Longitudo 17 – 30 µm, latitudo 3.0 – 4.5 µm. Area axialis angustissima, linearis, dilatans in aream centralem. Area centralis formans fasciam latam, cuneiformem. Raphe filiformis, ramis rectis, terminationibus raphis proximalibus unilateraliter leviter deflexis cum poris guttiformibus expansis, relative distantibus inter se. Terminationes raphis distales paene non discernandae in LM, falcatae. Striae fortiter radiatae in media parte valvae, abrupte convergentes ad apices, 12 – 14 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF90925842EBF8F0FDA39297.taxon	description	Valves narrowly lanceolate, slightly convex in the middle and gradually narrowing towards the capitate, narrowly rounded valve apices. Valve dimensions (n = 19): length 17 – 30 µm, width 3.0 – 4.5 µm. Axial area very narrow, widening towards the central area. Central area forming a broad, wedge-shaped fascia. Raphe filiform, straight with only slightly deflected central endings terminating in clearly droplike expanded, relatively distant, central pores. Terminal fissures almost indistinct in LM, probably sickle-shaped (Figs 22 – 23). Striae strongly radiate in the middle, becoming abruptly strongly convergent at the apices, 12 – 14 in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF90925842EBF8F0FDA39297.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 068, leg. B. Van de Vijver, coll. date 18 / 01 / 2009, slide no. BR- 4252 (holotype BR), slide PLP- 197 (isotype University of Antwerp, Belgium), slide ZU 8 / 28 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF90925842EBF8F0FDA39297.taxon	biology_ecology	Habitat: — Pinnularia subcarteri is a rare species on Livingston Island and was found in a few samples. The type population was sampled from the sandy bottom of a small pool near the southern beaches, with an almost circumneutral pH (7.2) and a low specific conductance (<100 µS / cm) value. The species was also observed in the surrounding moss vegetation. On Hurd Peninsula, the species was occasionally observed mostly on moss vegetations surrounding small water basins and in a small brook, flowing out from a shallow melt-water pool, with low specific conductance values (58 µS / cm).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF90925842EBF8F0FDA39297.taxon	etymology	Etymology: — The specific epithet refers to the close resemblance to P. carteri Krammer (2000: 48).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF90925842EBF8F0FDA39297.taxon	discussion	Observations: — Pinnularia subcarteri shows some similarities to P. diversa Østrup (1901: 273) and P. carteri. Both P. diversa and its variety subcapitata Krammer & Lange-Bertalot (in Krammer 2000: 46) differ, however, in having a larger width (5 – 6 µm vs 3.0 – 4.5) and a lower stria density (10 – 12 vs. 12 – 14 in 10 µm). Pinnularia carteri is also distinctly wider (4.8 – 5.2 µm) with a coarser striation pattern (10 – 11 striae in 10 µm) and has large central pores that are close together, in contrast to P. subcarteri, which has distant central pores. Rumrich et al. (2000, plate 144, figs 17 – 20) illustrate several valves identified as P. martinii Krasske (1939: 394) that are probably conspecific with P. subcarteri. However, comparison with type material of P. martinii (Van de Vijver et al., unpubl. res.) indicated that the illustrated valves in Rumrich et al. (2000) certainly do not belong to P. martinii sensu Krasske. The latter is characterized by more convex, less tumid valve margins, an axial area that is clearly widened towards the central area and a much larger central area (Lange-Bertalot et al. 1996, Van de Vijver et al., unpubl. res.).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF91925842EBFAF9FDD194CE.taxon	diagnosis	Valvae lineares ad angustissime lanceolatae, marginibus parallelis ad leviter convexis. Apices in speciminibus maioribus leviter protractae, late subrostratis, in speciminibus minorobus late rotundatae. Longitudo 21 – 28 µm, latitudo 3.6 – 4.5 µm. Area axialis angusta, linearis, non dilatans in aream centralem. Area centralis formans fasciam latam, aliquando asymmetricam. Raphe filiformis, ramis rectis, terminationibus raphis proximalibus unilateraliter leviter deflexis cum, extensis in aream centralem. Terminationes raphis distales paene non discernandae in LM, falcatae. Striae leviter ad moderate radiatae in media parte valvae, convergentes ad apices, 16 – 19 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF91925842EBFAF9FDD194CE.taxon	description	Valves linear to narrowly lanceolate with parallel to slightly convex margins. Apices in larger specimens slightly protracted and broadly subrostrate, in smaller valves clearly broadly rounded. Valve dimensions (n = 10): length 21 – 28 µm, width 3.6 – 4.5 µm. Axial area narrow, linear, almost not slightly widened towards the valve middle. Central area forming a large, occasionally asymmetrical, fascia, about ¼ to ⅓ of the valve length. Raphe straight with weakly deflected proximal endings, extending well beyond the last central striae, terminating in clearly expanded central pores, moderately distantly spaced. Distal raphe fissures barely visible, probably sickle-shaped. Striae weakly to moderately radiate near the centre, convergent at the apices, 16 – 19 in 10 µm. Longitudinal lines not visible in LM.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF91925842EBFAF9FDD194CE.taxon	materials_examined	Type: — Hurd Peninsula, Livingston Island, South Shetland Islands, sample A 24 / 2006, leg. R. Zidarova, coll. date 27 / 12 / 2005, slide no. BR- 4261 (holotype BR), slide PLP- 206 (isotype University of Antwerp, Belgium), slide ZU 8 / 27 (isotype BRM). Habitat: — The largest population of P. subaltiplanensis was observed on Hurd Peninsula where the species was found in low abundances in a small brook flowing out from a shallow lake with a low specific conductance (58 µS / cm) value and pH of 6.3. Occasionally the species was found in a wet moss vegetation growing around small puddles. On Byers Peninsula, only a few valves were observed.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF91925842EBFAF9FDD194CE.taxon	etymology	Etymology: — The specific epithet refers to its close resemblance to P. altiplanensis Lange-Bert., Krammer & Rumrich in Rumrich, Lange-Bert., & Rumrich 2000: 197).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF91925842EBFAF9FDD194CE.taxon	discussion	Observations: — Pinnularia subaltiplanensis is most similar to P. altiplanensis but the valves are narrower than the type population of P. altiplanensis from the Chilean Altiplano (3.6 – 4.5 vs. 4 – 6 µm in P. altiplanensis) giving them a more slender outlook. The central raphe endings in P. subaltiplanensis are more distantly spaced than in P. altiplanensis. Pinnularia laucensis is smaller, with a maximum length of up to 20 µm and a valve width of 3.3 – 4.5 µm compared to 21 – 28 µm and 3.6 – 4.5 µm in subaltiplanensis, and has less radiate, widely spaced striae (11 – 14 vs. 16 – 19 in 10 µm). Other similar species are P. schoenfelderi, P. frauenbergiana Reichardt (1985: 182) and P. kuetzingii Krammer (1992: 104), all known from Europe (Krammer 2000). Pinnularia schoenfelderi can be easily separated based on the larger valve width (5 – 7 µm vs 3.6 – 4.5 µm) and lower stria density (13 – 16 vs 16 – 19 in 10 µm), as well as the smaller central area, less distantly spaced central raphe endings and a more lanceolate valve outline. Pinnularia frauenbergiana has comparable valve dimensions but a more elliptic-lanceolate valve outline and more densely spaced striae (18 – 22 in 10 µm). Pinnularia kuetzingii differs by having a higher stria density of 18 – 20 in 10 µm (vs. 16 – 19 in 10 µm) and less distantly spaced proximal pores. Finally, P. bertrandii, according to Rumrich et al. (2000) is similar to P. altiplanensis, has broad subcapitate valve ends and an axial area that is clearly widens towards the central area (Krammer 2000).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF92925B42EBFBA3FC9697CB.taxon	description	Valves linear with almost straight margins and non-protracted, cuneate obtuse apices. Valve dimensions (n = 10): length 14 – 23 µm, width 4.3 – 5.0 µm. Axial area narrow, linear, not widened towards the central area. Central area forming a large rectangular, asymmetrical fascia due to irregular shortening of striae near the central area. Raphe straight. Proximal raphe endings clearly deflected with expanded, drop-like raphe pores. Distal raphe fissures moderately large, sickle-shaped. Striae parallel, weakly convergent towards the ends 10 – 12 in 10 µm. Central striae bordering the central area, weakly radiate. Longitudinal lines absent. Habitat: — Pinnularia strictissima has been only found in one sample on Byers Peninsula. This population was sampled from the sandy bottom of a small pool near the southern beaches, with an almost circumneutral pH (7.2) and a low specific conductance (<100 µS / cm) value. Observations: — The Antarctic population of Pinnularia strictissima matches exactly the description provided by Manguin (1964), described from the Peruvian Andes in a swamp at an altitude between 4000 and 4100 m. The species can be confused with several small-celled Pinnularia species with a low stria density, a rather large fascia and an almost parallel striation pattern, such as P. intermedia (Lagerstedt 1873: 23) Cleve (1895: 80), P. lagerstedtii (Cleve 1895: 87) Cleve-Euler (1934: 57), P. schimanskii Krammer (2000: 32), P. cuneorostrata (Manguin in Bourrelly & Manguin 1954: 36) Van de Vijver & Le Cohu (in Van de Vijver et al. 2002: 83), P. incognita Krasske (1939: 397), P. palatina Lange-Bert. & W. Krüger (in Werum & Lange-Bert. 2003: 171) and even P. obscura. The most similar species is P. intermedia but the latter can be distinguished in having typical capitate to rostrate apices (in contrast to the cuneate obtuse apices in P. strictissima), large valve dimensions (length: 18 – 40 µm vs. 14 – 23 µm) and less distinct distal raphe fissures. Moreover, the striae in P. intermedia are radiate in the middle whereas in P. strictissima, the striae are almost entirely parallel. Pinnularia lagerstedtii, P. schimanskii and P. incognita have usually longer, more elongated valves (up to 35 µm) with more broadly rounded valve apices. Pinnularia cuneorostrata, up to now only found on the sub- Antarctic islands in the southern Indian Ocean, has a lower valve width (2.5 – 4.5 µm vs. 4.3 – 5.0) resulting in more elongated, thinner valves. Recently P. palatina was described from a spring in Germany but represents valves with bluntly rounded valve apices, a more elongated valve outline and less parallel striae. Finally, P. obscura has a different striation pattern with clearly radiate striae changing into distinctly convergent near the apices. The valve outline differs with typical rostrate apices.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF92925B42EBFFCDFDD294FF.taxon	description	Valves linear with parallel or, in larger specimens, weakly undulated margins, and non-protracted, broadly rounded apices. Valve dimensions (n = 11): length 25 – 35 µm, width 5.0 – 6.5 µm. Axial area narrow, linear, clearly widening towards the central area. Central area forming a large rhombic fascia, about 1 / 3 to 1 / 4 of valve length, expanded to the margins. Raphe slightly curved. Central raphe endings extending into the central area well beyond the last central striae, unilaterally deflected and finishing in relatively distant drop-like pores. Terminal fissures almost indistinct,? - shaped. Striae strongly radiate in the middle, abruptly changing their direction to convergent toward the valve ends, 11 – 13 in 10 µm. Longitudinal lines absent. Habitat and distribution: — This is an extremely rare species on Livingston Island. Only a few valves were found on Hurd Peninsula, in streams, in a vegetation of wet mosses close to streams, brooks or puddles.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF92925B42EBFFCDFDD294FF.taxon	discussion	Observations: — These Antarctic specimens belong to the complex of species around P. divergentissima (Grunow in Cleve & Möller 1879: 186) Cleve (1895: 77) sensu Krammer (2000). Pinnularia divergentissima and its varieties can be separated based on a different valve outline, having mostly convex margins and smaller subrostrate to capitate valve ends, as well as by a slightly higher number of striae (according to Krammer 2000: 12 – 14 vs 11 – 13 in 10 µm) and a smaller central area. The most similar species is P. krammeri Metzeltin (in Lange-Bertalot & Metzeltin 1996: 98), described from Finland. The main differences between the Antarctic population and P. krammeri include a larger valve width of P. krammeri (6.7 – 7.8 µm vs. 5.0 – 6.5 µm), a comparably smaller central area and more closely spaced proximal raphe endings. Since only a few valves have been observed, it is too early to conclude whether they should be described as an independent species or belong to P. krammeri.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925A42EAFBA3FDF697F9.taxon	diagnosis	Valvae lineares ad lineares-lanceolatae, marginibus parallellis ad leviter convexis in media parte valvae, graduatim decrescentibus in apices non-protractos, anguste rotundatos. Longitudo 25 – 38 µm, latitudo 4.6 – 6.0 µm. Area axialis angusta, linearis, aliquando dilatans in aream centralem. Area centralis formans fasciam latam, cuneiformem ad rectangularem. Raphe filiformis, ramis leviter curvatis. Terminationes raphis proximales extensae ultra strias centrales, deflexae cum poris parvis expansis. Fissurae raphis distales paene non discernandae in LM, similes signo interrogationis. Striae radiatae in media parte valvae, convergentes ad apices, 10 – 12 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925A42EAFBA3FDF697F9.taxon	description	Valves linear to linear-lanceolate with parallel to weakly convex margins, gradually narrowing towards the non-protracted, narrowly rounded apices. Valve dimensions (n = 25): length 25 – 38 µm, width 4.6 – 6.0 µm. Axial area narrow, linear, occasionally widening towards the central area. Central area forming a large, bowtie-shaped to rectangular fascia. Raphe filiform with weakly curved raphe branches. Proximal raphe endings extending well beyond the last central striae, deflected and terminating in small, expanded raphe pores. Distal raphe fissures difficult to resolve in LM,? - shaped. Striae radiate near the valve middle, becoming convergent towards the apices, 10 – 12 in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925A42EAFBA3FDF697F9.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 068, leg. B. Van de Vijver, coll. date 18 / 01 / 2009, slide no. BR- 4253 (holotype BR), slide PLP- 198 (isotype University of Antwerp, Belgium), slide ZU 8 / 20 (isotype BRM). Habitat: — The type population of Pinnularia australoschoenfelderi was sampled from the sandy bottom of a small pool near the southern beaches on Byers Peninsula, with an almost circumneutral pH (7.2) and a low specific conductance (<100 µS / cm) value. The species was also found on Hurd Peninsula, usually rare but more abundant in soil under wet moss vegetations and among wet mosses surrounding shallow pools.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925A42EAFBA3FDF697F9.taxon	etymology	Etymology: — The specific epithet refers to the geographic distribution of the species (Latin ‘ australis ’ meaning southern) and to its similarity to Pinnularia schoenfelderi.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925A42EAFBA3FDF697F9.taxon	discussion	Observations: — Pinnularia australoschoenfelderi can be confused with P. schoenfelderi; the latter differs in having a higher stria density (13 – 16 in 10 µm vs. 10 – 12 in 10 µm) giving the species a finer striation pattern. Pinnularia frauenbergiana has even more striae per 10 µm (18 – 22 vs. 10 – 12 in 10 µm). Pinnularia obscura has a more irregular striation pattern with a clear shift in stria direction halfway between the central area and apices. Pinnularia obscuriformis Krammer (2000: 51) has comparable dimensions but more linear valves with acutely rounded apices.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925442EBFE2AFE919139.taxon	diagnosis	Valvae clare lanceolatae ad etiam rhombicae-lanceolatae marginibus semi-rhomboidalibus ad convexis, apicibus leviter ad moderate protractis, cuneiformibus. Longitudo 22 – 32 µm, latitudo 4.9 – 6.0 µm. Area axialis angusta, linearis, aliquando dilatans in aream centralem. Area centralis formans fasciam cuneiformem latam. Raphe filiformis, ramis leviter curvatis. Terminationes raphis proximales leviter unilateraliter deflexae cum poris paene indistinctis. Fissurae raphis distales similes signo interrogationis. Striae moderate ad fortiter radiatae in media parte valvae, moderate ad fortiter convergentes ad apices, 9 – 10 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925442EBFE2AFE919139.taxon	description	Valves clearly lanceolate to even rhombic-lanceolate with semi-rhomboidal to convex margins and cuneiform, weakly to moderately protracted apices. Valve dimension (n = 33): length 22 – 32 µm, width 4.9 – 6.0 µm. Axial area narrow, linear, slightly widened towards the central area. Central area large, forming a bowtie-shaped fascia. Raphe filiform with weakly curved raphe branches. Proximal raphe endings slightly deflected to one side, with small, almost indistinct central pores. Terminal fissures? - shaped. Striae moderately to strongly radiate in the middle, becoming moderately to strongly convergent towards the ends, 9 – 10 in 10 µ m. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925442EBFE2AFE919139.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BYS 012, leg. B. Van de Vijver, coll. date 14 / 01 / 2009, slide no. BR- 4254 (holotype BR, slide PLP- 199 (isotype University of Antwerp, Belgium), slide ZU 8 / 23 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925442EBFE2AFE919139.taxon	biology_ecology	Habitat: — Pinnularia magnifica was frequently found on Livingston Island in small streams, pools and seepage areas with an alkaline pH and low specific conductance. The species has not been recorded in larger lakes. It is also observed in very low abundance on semi-wet and moist moss vegetation surrounding shallow water pools and on soil.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925442EBFE2AFE919139.taxon	etymology	Etymology: — The specific epithet represents the esthetical appreciation of the authors for this species (Latin magnificus means splendid, magnificent).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF93925442EBFE2AFE919139.taxon	discussion	Observations: — Pinnularia magnifica can hardly be confused with other Pinnularia species, based on its combination of radiate striae, low stria density and large, bowtie-shaped fascia. Pinnularia acoricola Hust. (in A. Schmidt 1934: 390) has a different striation pattern with a sudden shift in direction halfway down the valve and a higher stria density (13 – 16 in 10 µm vs. 9 – 10 in 10 µm). Pinnularia obscura shows a comparable shift in stria direction to P. acoricola and has a different valve outline with more rostrate apices. Another similar species is P. cuneola Reichardt (1981: 501) but it is larger (width 6 – 8 µm vs. 4.9 – 6 µm) with less protracted apices. The closely related P. insidiosa Manguin (1964: 81), described from the Peruvian Andes, has a similar striation pattern and a similar stria density but shows a different valve outline with less protracted apices (Manguin 1964).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925442EBF96AFC529467.taxon	diagnosis	Valvae lineares marginibus plerumque undulatis, parallelis ad leviter convexis, apicibus late rotundatis, leviter protractis, rostratis ad subcapitatis. Longitudo 26 – 50 µm, latitudo 5.3 – 6.7 µm. Area axialis moderate lata, lanceolata, dilatans in aream centralem. Area centralis formans fasciam angustam ad moderate latam, rhomboidem, asymmetricam. Raphe filiformis, ramis leviter curvatis. Terminationes raphis proximales leviter unilateraliter deflexae cum poris expansis, guttiformibus. Fissurae raphis distales falcatae. Striae moderate radiatae in media parte valvae, convergentes ad apices, 12 – 14 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925442EBF96AFC529467.taxon	description	Valves linear with usually undulating, parallel to weakly convex margins and weakly protracted, rostrate to subcapitate, broadly rounded apices. Larger specimens with undulated margins. Valve dimensions (n = 25): length 26 – 50 µm, valve breadth 5.3 – 6.7 µm. Axial area relatively large, lanceolate, widening toward the central area. Central area forming a narrow to moderately broad, rhomboid, usually asymmetrical fascia. Striae gradually becoming shorter towards the valve middle. Raphe filiform with slightly curved raphe branches. Proximal raphe endings clearly deflected with expanded droplike pores. Terminal fissures distinct, sickle-shaped. Striae moderately radiate in the middle, convergent at the ends, 12 – 14 in 10 µm. Longitudinal lines absent	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925442EBF96AFC529467.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 003, leg. B. Van de Vijver, coll. date 09 / 01 / 2009, slide no. BR- 4262 (holotype BR), slide PLP- 207 (isotype University of Antwerp, Belgium), slide ZU 8 / 24 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925442EBF96AFC529467.taxon	biology_ecology	Habitat: — Pinnularia microstauroides was frequently observed in larger lakes on Byers Peninsula and only occasionally on Hurd Peninsula, where it was previously reported from as P. microstauron var. rostrata Krammer (Zidarova 2008: 30, fig. 27). The largest populations were found in coastal lakes on Byers Peninsula with a higher specific conductance (150 – 250 µS / cm) and higher nutrients due to the presence of marine mammals and penguins.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925442EBF96AFC529467.taxon	discussion	Observations: — Pinnularia microstauroides clearly belongs to the complex of species around P. microstauron (Ehrenb. 1843) Cleve (1891: 28). The latter is a highly variable species and probably represents a complex rather than a single species. Pinnularia microstauron, based on the account in Krammer (2000), is larger with a valve breadth of 10.0 – 12.4 µm and usually with a lower stria density (9 – 11 in 10 µm vs. 12 – 14 in 10 µm). The undulating margins in P. microstauroides are also rarely observed in P. microstauron. A large number of varieties (later raised to the species level by Kulikovskiy et al. 2010), have already been described within the P. microstauron - complex, usually reflecting the local variability of the species. However, according to the original description in Krammer (2000), some of these varieties have a higher valve width and / or a lower stria density: P. nanomicrostauron Kulikovskiy, Lange-Bert. & Metzeltin (2010: 361) has a width of 6.0 – 7.0 µm with 10 – 11 striae in 10 µm whereas P. microstauropsis Kulikovskiy, Lange-Bert. & Metzeltin (2010: 361) has a width of 6.5 – 8.0 µm and 10 – 12 striae in 10 µm.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925642EBFCA0FE729775.taxon	diagnosis	Valvae ellipticae-lanceolatae ad anguste ellipticae marginibus convexis, graduatim decrescentibus in apices, apicibus non-protractis, obtuse rotundatis. Longitudo 30 – 53 µm, latitudo 7.3 – 9.3 µm. Area axialis moderate lata, lanceolata, clare dilatans in aream centralem. Area centralis formans fasciam cuneiformem potius latam. Raphe filiformis, ramis leviter curvatis. Terminationes raphis proximales deflexae cum poris expansis, guttiformibus. Fissurae raphis distales falcatae. Striae fortiter radiatae in media parte valvae, graduatim sed non abrupte convergentes ad apices, 9 – 10 in 10 µm. Lineae speciosae longitudinales nullae. Valves elliptic-lanceolate to narrowly elliptic in smaller valves with convex margins gradually tapering towards the bluntly rounded, non-protracted apices. Valve dimensions (n = 10): length 30 – 53 µm, width 7.3 – 9.3 µm. Axial area moderately broad, lanceolate, clearly widening towards the central area. Central area forming a bowtie-shaped, rather large fascia. Raphe filiform with slightly curved raphe branches. Proximal raphe endings deflected terminating in droplike, expanded pores. Distal raphe fissures sickle-shaped. Striae strongly radiate near the valve middle, gradually but not abruptly becoming convergent towards the apices, 9 – 10 in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925642EBFCA0FE729775.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BYS 012, leg. B. Van de Vijver, coll. date 14 / 01 / 2009, slide no. BR- 4255 (holotype BR), slide PLP- 200 (isotype University of Antwerp, Belgium), slide ZU 8 / 21 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925642EBFCA0FE729775.taxon	biology_ecology	Habitat: — Small populations of P. hamiltonii have been observed in several samples collected in a wide variety of habitats on Byers Peninsula ranging from small pools and streams to lakes and seepage areas with a pH-range of 7.3 – 7.9 and a specific conductance <100 µS / cm.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925642EBFCA0FE729775.taxon	etymology	Etymology: — The species is named after our colleague Paul Hamilton (Museum of Nature, Ottawa, Canada) in recognition of his taxonomic work on diatoms.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9D925642EBFCA0FE729775.taxon	discussion	Observations: — Pinnularia hamiltonii can hardly be confused with other Pinnularia taxa. Only a few species are similar to Pinnularia hamiltonii: P. suchlandtii Hust. (in A. Schmidt 1934: 388), P. superdivergentissima Chaumont & Germain (1976: 587 – 588), P. cuneola, P. acutobrebissonii Kulikovskiy, Lange-Bert. & Metzeltin (2010: 361) and P. crozetii Van de Vijver & Le Cohu (in Van de Vijver et al. 2002: 82). The most similar species is probably P. crozetii, described from the sub-Antarctic Crozet archipelago (Van de Vijver et al. 2002), but the latter differs in being usually larger (valve width up to 10.5 µm) with gradually shortening striae in the central area whereas P. hamiltonii lacks these shorter striae. P. acutobrebissonii is larger (width 10 – 11.4 µm vs. 7.3 – 9.3 µm) with more acutely rounded apices and a smaller central area (Krammer 2000). P. superdivergentissima has strictly linear valves with parallel margins (Chaumont & Germain 1976) and both P. suchlandtii and P. cuneola have a more rhombic-lanceolate valve outline (Krammer 2000).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9F925042EBFF98FBB39011.taxon	diagnosis	Valvae lineares in speciminibus maioribus ad lineares-ellipticae in speciminibus minoribus marginibus parallellae ad moderate convexis. Specimina marginibus leviter undulates. Apices late subrostrati-subcapitati, leviter protracti ad late rotundati in specimibus minoribus. Longitudo 30 – 93 µm, latitudo 8.4 – 14.6 µm. Area axialis distincte lanceolata, angusta in apicibus, dilatans in aream centralem. Area centralis formans fasciam rhombicam, plerumque asymmetricam in speciminibus majoribus, latam. Striae centrales nonnullae abbreviatae in area centrali speciminum maiorum. Raphe lateralis terminationibus raphis proximalibus deflexis cum poris magnis guttiformibus. Fissurae raphis distales falcatae. Striae leviter ad moderate radiatae in media parte valvae, parallelae ad moderate convergentes ad apices, 12 – 15, pro parte maxima 13 – 14 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9F925042EBFF98FBB39011.taxon	description	Valves linear in larger specimens to linear-elliptic in smaller specimens with parallel to moderately convex margins. Larger valves with weakly undulated margins. Valve apices broadly subrostrate-subcapitate, weakly protracted to broadly rounded in smaller ones. Valve dimensions (n = 45): length 30 – 93 µm, width 8.4 – 14.6 µm. Axial area distinctly lanceolate, narrow near the apices and widening towards the central area. Central area forming a large rhombic, usually asymmetrical, fascia in larger specimens. Smaller specimens only with rhombic to rounded central area with shortened striae bordering the area. Raphe lateral with deflected proximal raphe endings terminating in droplike large pores. Distal raphe fissures sickle-shaped. Striae weakly to moderately radiate in the middle, almost parallel to moderately convergent towards the apices, 12 – 15, mostly 13 – 14, in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9F925042EBFF98FBB39011.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 061, leg. B. Van de Vijver, coll. date 17 / 01 / 2009, slide no. BR- 4256 (holotype BR), slide PLP- 201 (isotype University of Antwerp, Belgium), slide ZU 8 / 19 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9F925042EBFF98FBB39011.taxon	biology_ecology	Habitat: — Pinnularia australomicrostauron is one of the most common species of Pinnularia on Livingston Island, often forming very large populations in a wide variety of habitats, both aquatic (pools and larger lakes) and terrestrial (e. g. wet soil and mosses around small water bodies).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9F925042EBFF98FBB39011.taxon	etymology	Etymology: — The specific epithet refers to the geographic distribution of the species (Latin: ‘ australis ’ meaning southern) and the similarity to Pinnularia microstauron.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9F925042EBFF98FBB39011.taxon	discussion	Observations: — Pinnularia australomicrostauron mostly resembles P. ventricodecrescens Kulikovskiy, Lange-Bert. & Metzeltin (2010: 365), P. microstauron and P. rhombarea Krammer (in Metzeltin & Lange- Bertalot 1998: 185); it has been reported from Antarctica as P. microstauron. Pinnularia microstauron was originally described by Ehrenberg from plant roots in Brazil and until recently it was believed to be a polymorph species. Krammer (2000) suggested, however, that its plasticity might not be so large. According to his assumption, P. microstauron var. microstauron lacks undulated margins and has broadly rostrate to wedge-shaped ends. Parts of the Pinnularia australomicrostauron populations clearly show valves with undulated margins and ends that are broadly subrostrate to subcapitate. The new species has a higher stria density than normally observed in P. microstauron (9 – 11, rarely 15 in 10 µm vs. 13 – 14 in 10 µm in P. australomicrostauron). The most distinctive feature separating the two species is the distance between the central raphe endings, which is much larger in the P. australomicrostauron when compared to Pinnularia microstauron s. s. Pinnularia microstauron var. nonfasciata Krammer (2000: 74) usually lacks a fascia, in contrast to P. australomicrostauron, where only in smaller individuals is a fascia absent. Other varieties of P. microstauron listed in Krammer (2000) are small enough not to be confused with P. australomicrostauron. Pinnularia rhombarea has a rather similar valve outline but is generally wider (width 10.5 – 16. o µm vs. 8.4 – 14.6 µm) with a lower stria density (9 – 11 in 10 µm vs. 13 – 14 in 10 µm). Probably the most similar species is P. ventricodecrescens, originally described from South Georgia as P. krasskei var. ventricosa. Analysis of the type material indicated that in the latter, also the larger specimens lack a fascia, the valves have a higher valve width (13 – 16 µ m vs. 8.4 – 14.6 µ m) and clearly subcapitate apices. The longest specimens of P. australomicrostauron closely resemble P. krasskei, also described from South Georgia (Krammer 2000). However, based on the analysis of type material, the latter always has strictly parallel margins with broadly rounded, never protracted apices, a larger valve width (15 – 16 µm vs. 14.6 in the largest specimens of P. australomicrostauron) and a lower stria density (9 – 11 in 10 µm vs. 12 – 15 in 10 µm).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9A925242EBFBA3FB8691C2.taxon	diagnosis	Valvae lineares marginibus paene parallelis, apicibus non-protractis, late rotundatis. Longitudo 66 – 110 µm, latitudo 14 – 19 µm. Area axialis linearis-lanceolatae, potius lata, dilatans in aream centralem. Area centralis rhombica formans fasciam rectangularem potius parvam, maculis rotundatis in marginibus. Raphe lateralis, ramis leviter undulatis. Terminationes raphis proximales rectae. Pori centrales annicibus lateralis. Fissurae raphis distales unciformes. Striae moderate radiatae in media parte valvae, graduatim fortiter convergentes ad apices, 9 – 11 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9A925242EBFBA3FB8691C2.taxon	description	Valves linear with almost parallel margins and broadly rounded, non-protracted apices. Valve dimensions (n = 12): length 66 – 110 µm, width 14 – 19 µm. Axial area linear-lanceolate, rather broad, widening toward the central area. Central area rhomboid, forming a rather narrow, rectangular fascia with rounded thickenings at the margins, visible in LM. Raphe lateral, slightly undulating with straight proximal raphe endings. Central pores with lateral annexes. Distal raphe fissures bayonet - shaped. Striae moderately radiate in the middle, gradually becoming strongly convergent near the apices, 9 – 11 in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9A925242EBFBA3FB8691C2.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 047, leg. B. Van de Vijver, coll. date 14 / 01 / 2009, slide no. BR- 4257 (holotype BR), slide PLP- 202 (isotype University of Antwerp, Belgium), slide ZU 8 / 17 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9A925242EBFBA3FB8691C2.taxon	biology_ecology	Habitat: — Pinnularia australodivergens could be found in a few large lakes on the central plateau of Byers Peninsula near Limnopolar lake. The lakes are characterized by a weakly alkaline pH (7.2 – 7.6) and a low specific conductance (<100 µS / cm).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9A925242EBFBA3FB8691C2.taxon	etymology	Etymology: — The specific epithet refers to the geographic distribution of the species (Latin: ‘ australis ’ meaning southern).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9A925242EBFBA3FB8691C2.taxon	discussion	Observations: — Pinnularia australodivergens clearly belongs to the P. divergens W. Smith (1853: 57) - complex based on the valve outline, dimensions and the typical rounded thickenings in the central area. The species shows some similarity with several other species and varieties in this complex, some recently raised to species rank (Kulikivskiy et al. 2010) such as P. canadodivergens Kulikovskiy, Lange-Bert. & Metzeltin (2010: 360), P. divergens var. sublineariformis Krammer 2000: 62) and P. biconstrictoides Kulikovskiy, Lange-Bert. & Metzeltin (2010: 360). P. canadodivergens can be distinguished by its more swollen middle part, the typical markings along the axial area and the lower number of striae (8 – 10 vs. 9 – 11 in 10 µm). Pinnularia divergens var. sublineariformis is much smaller with a lower valve width (11.0 – 13.5 µm vs. 14 – 19 µm). Finally, P. biconstrictoides has a different valve outline with clearly swollen central and terminal parts of the valve, a large, rhomboid, central area and usually larger valve dimensions.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9B925242EBF836FC6C94FD.taxon	diagnosis	Valvae lanceolatae ellipticae-lanceolatae marginibus convexis, apicibus graduatim decrescentibus, aliquando leviter protractis, late rotundatis. Longitudo 50 – 65 µm, latitudo 10 – 13 µm. Area axialis moderate lata, lanceolata, graduatim dilatans in aream centralem. Area centralis rhombica formans fasciam cuneiformem moderate latam, maculis rotundatis in marginibus. Raphe lateralis, ramis clare undulatis. Terminationes raphis proximales rectae ad leviter deflexae. Pori centrales annicibus lateralis. Fissurae raphis distales unciformes. Striae fortiter radiatae in media parte valvae, distincte convergentes ad apices, 10 – 12 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9B925242EBF836FC6C94FD.taxon	description	Valves lanceolate to elliptic-lanceolate with convex margins and broadly rounded, gradually narrowing, sometimes slightly protracted apices. Valve dimensions (n = 10): 50 – 65 µm, width 10 – 13 µm. Axial area moderately large, lanceolate, gradually widening towards the central area. Central area rhomboid, forming a bowtie-shaped moderately large fascia with rounded thickenings at the margin. Raphe lateral, clearly undulating with straight to weakly deflected proximal raphe endings. Raphe pores with lateral annexes. Distal fissures bajonet-shaped. Striae strongly radiate near the valve centre, becoming distinctly convergent towards the apices, 10 – 12 in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9B925242EBF836FC6C94FD.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 047, leg. B. Van de Vijver, coll. date 14 / 01 / 2009, slide no. BR- 4258 (holotype BR), slide PLP- 203 (isotype University of Antwerp, Belgium), slide ZU 8 / 26 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9B925242EBF836FC6C94FD.taxon	biology_ecology	Habitat: — Pinnularia sergiplaiana could be found in several large lakes on the central plateau of Byers Peninsula near Limnopolar lake. The type population was sampled from the sediment of a large lake, characterized by a weakly alkaline pH (7.4) and a low specific conductance (108 µS / cm). So far, the species has been rarely found on Hurd Peninsula where from it was previously reported as P. media (Krammer 2000: 61) Kulikovskiy, Lange-Bert. & Metzeltin (2010: 359) (Zidarova 2008, p. 30, fig. 24).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9B925242EBF836FC6C94FD.taxon	etymology	Etymology: – The species is named in honor of our colleague Sergi Pla (Madrid, Spain), in recognition of his contribution to the knowledge of Antarctic algae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF9B925242EBF836FC6C94FD.taxon	discussion	Observations: — This new species clearly belongs to the complex of taxa around P. divergens, based on the presence of the typical rounded thickenings in the central area and the lateral annexes to the proximal raphe pores. Most of the species and varieties belonging to this complex are usually larger (Krammer 2000). Pinnularia divergens has a valve width of 14 – 19 µm (vs. 10 – 13 µm) and has clearly capitate to subcapitate apices. Pinnularia media has similar valve dimensions but is characterized by clearly capitate apices and lacks the typical fascia. Pinnularia livingstonensis sp. nov. (see below) can be distinguished by its typical parallel margins and its broadly rounded apices. Pinnularia crozetii lacks the rounded thickenings in the central area and has a more lanceolate valve outline. Pinnularia divergentissima (Kütz. 1844: 93) Rabenh. (1864: 222) has a somewhat similar valve outline but lacks the central thickenings.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF84924C42EBFC6CFC5A962B.taxon	diagnosis	Valvae lineares marginibus paene parallelis, apicibus late rotundatis, non-protractis. Longitudo 44.7 – 72.3 µm, latitudo 10 – 12.8 µm. Area axialis potius lata, linearis-lanceolata, dilatans in aream centralem. Area centralis formans fasciam rhombicam latam, maculis rotundatis in marginibus. Raphe lateralis, ramis leviter undulatis. Terminationes raphis proximales leviter deflexae cum poris indistinctis. Pori centrales annicibus lateralis. Fissurae raphis distales unciformes. Striae moderate ad fortiter radiatae in media parte valvae, graduatim moderate ad fortiter convergentes ad apices, 11 – 12 in 10 µm. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF84924C42EBFC6CFC5A962B.taxon	description	Valves linear with almost parallel margins and very broadly rounded, non-protracted apices. Valve dimensions (n = 53): length 44.7 – 72.3 µm, width 10.0 – 12.8 µm. Axial area linear-lanceolate, rather broad, widening toward the central area. Central area forming a large, rhomboid fascia with rounded thickenings at the margin, visible in LM. Raphe lateral, only slightly undulating with straight to only very weakly deflected proximal raphe endings and inconspicuous central pores, bearing small lateral annexes. Distal raphe fissures bajonetshaped. Striae moderately to strongly radiate in the middle, gradually becoming moderately to strongly convergent towards the ends, (10) 11 – 12 in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF84924C42EBFC6CFC5A962B.taxon	materials_examined	Type: — Hurd Peninsula, Livingston Island, South Shetland Islands, sample 5 b / 05, leg. R. Zidarova, coll. date 25 / 01 / 2005, slide no. BR- 4259 (holotype BR), slide PLP- 204 (isotype University of Antwerp, Belgium), slide ZU 8 / 22 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF84924C42EBFC6CFC5A962B.taxon	biology_ecology	Habitat: — Pinnularia livingstonensis is most abundant in a sample taken on Hurd Peninsula from very wet mosses close to a brook running down on a rocky surface, at about 70 m from the sea shore near Caleta Argentina Bay. The species was previously misidentified and reported as P. divergens var. sublinearis P. T. Cleve (1895: 79) (Zidarova 2008: 30, figs 25 & 26) whereas the larger forms were earlier reported as P. divergens f. biconstricta (Cleve-Euler 1939: 15) Cleve-Euler (1955: 53), which probably represent initial cells of the same species.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF84924C42EBFC6CFC5A962B.taxon	etymology	Etymology: — The specific epithet refers to Livingston Island where the species was first discovered.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF84924C42EBFC6CFC5A962B.taxon	discussion	Observations: — Pinnularia livingstonensis belongs to the P. divergens - complex based on the central rounded thickenings and the annexes to the proximal raphe pore (Krammer 2000). Pinnularia divergens var. subbacillaris Krammer (2000: 62) has a similar valve outline but is narrower (width 7.6 – 9.0 µm vs. 10.0 – 12.8 µm) with a higher stria density (12 – 14 vs. 11 – 12 in 10 µm). Pinnularia canadodivergens has slightly larger dimensions, a lower stria density (8 – 10 vs. 11 – 12 in 10 µm) and a smaller fascia. Pinnularia divergens var. sublineariformis, described from Bavaria, Europe, has comparable dimensions but a lower stria density (10 vs. 11 – 12 in 10 µm). All other varieties of Pinnularia divergens, listed in Krammer (2000), are easily distinguished from the Antarctic species by outline, dimensions and shape of the central area. Somewhat similar in outline to P. livingstonensis is P. parvulissima Krammer (2000: 95) but the latter has typical depressions in the central area and lacks the rounded thickenings.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF85924F42EBFE6DFEA09733.taxon	description	Valves broadly elliptic-lanceolate with clearly convex margins and protracted, rostrate ends. Valve dimensions (n = 25): length 32 – 42 µ m, width 9.7 – 11.3 µm. Axial area linear to linear-lanceolate, narrow, slightly widening towards the central area. Central area a large, bow-tie-shaped fascia. Raphe filiform with weakly curved branches. Central raphe endings deflected to the secondary side with large, almost triangular-shaped, central pores. Terminal fissures bent to one side, opposite to the central endings. Striae geniculate, radiate near the centre, becoming convergent near the valve ends, 13 – 15 in 10 µm. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF85924F42EBFE6DFEA09733.taxon	biology_ecology	Habitat: — The species is rather rare on Livingston Island. On Hurd Peninsula, it was found relatively abundantly in only one sample taken from a Sanionia georgico-uncinata vegetation, growing around a periodically drying shallow brook close to the sea. On Byers Peninsula, the species was more common. The largest population was found on wet soil close to the sea with a clear presence of elephant seal input (Van de Vijver, pers. obs.). The species seems to prefer more aerial circumstances influenced by biogenic input such as penguin rookeries and elephant seal wallows (Van de Vijver et al. 2002).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF85924F42EBFE6DFEA09733.taxon	discussion	Observations: — There is much confusion about the correct taxonomic identity of Pinnularia austroshetlandica. In 1954, Manguin (in Bourrelly & Manguin 1954) described a new species of Pinnularia he named P. kolbei. The name kolbei had already been used by Mölder (1952: 27; see Fukushima et al. 2001: 107) making a new name for Manguin’s species necessary; Fukushima et al. proposed P. parakolbei Fukushima, Ko-Bayashi & Yoshitake (Fukushima et al. 2001: 108) as a substitute name. However, populations observed from the Falkland Islands did not entirely conform to Manguin’s original description as they lacked the typical rostrate apices, a feature clearly stated (‘ étirées rostrées aux extrémités ’) and illustrated by Manguin (in Bourrelly & Manguin 1954: fig. 52). Van de Vijver et al. (2002) separated the non-rostrate forms from P. kolbei identifying them as P. bottnica. Examination of type material of P. kolbei (Van de Vijver, unpubl. res., slide number AD 9087). both rostrate and non-rostrate specimens present in the same population; no other morphological or biometrical differences could be found. Additionally, detailed analysis of some large populations from other southern Indian Ocean islands yielded the same result (Van de Vijver, unpubl. res.). Therefore, it can be concluded that the P. bottnica populations of Ile de la Possession (Van de Vijver et al. 2002) and the P. parakolbei population from the Falkland Islands (Fukushima et al. 2001) are conspecific and the name parakolbei should be used for both the rostrate and the non-rostrate specimens. Fukushima et al. (2001) considered Pinnularia austroshetlandica to be similar to but distinct enough from P. parakolbei since the strongly protruding ends and the almost straight raphe distinguished the former. Type material of Navicula austroshetlandica (the basionym of Pinnularia austroshetlandica) has not yet been located. A careful examination of the description and drawing in Carlson (1913) and its comparison with specimens from different parakolbei - populations from the entire (sub-) Antarctic Region did not reveal any significant differences between P. austroshetlandica and P. parakolbei. Thus, P. austroshetlandica, P. parakolbei and P. kolbei sensu Manguin are considered synonyms and P. austroshetlandica should therefore be given priority. Another name that may need adding is Navicula nivorum and its variety elongata. Although the original material is apparently no longer available, the descriptions and drawings match clearly P. austroshetlandica.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF86924942EBFF45FE7B9067.taxon	diagnosis	Valvae lineares-lanceolatae ad ellipticae-lanceolatae in speciminibus minoribus marginibus clare convexis, apicibus late capitatis, semper distincte angustioribus quam media parte valvae. Longitudo 25 – 37 µm, latitudo 8.4 – 9.6 µm. Area axialis angusta, leviter dilatans in aream centralem. Area centralis formans fasciam cuneiformem latam. Raphe filiformsi, ramis leviter curvatis. Terminationes raphis proximales leviter deflexae cum poris indistinctis. Fissurae raphis distales unilateraliter flexae. Striae in media parte valvae curvatae, moderate ad fortiter radiatae, parallelae ad leviter convergentes ad apices, 13 – 15 in 10 µm. Striae abbreviatae nonnulae in area centrali. Lineae speciosae longitudinales nullae.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF86924942EBFF45FE7B9067.taxon	description	Valves linear-lanceolate to elliptic-lanceolate in smaller individuals, with clearly convex margins and broadly capitate apices, always distinctly narrower than the valve middle; in smaller specimens barely offset. Shoulders between apices and valve middle absent. Valve dimensions (n = 20): length 25 – 37 µm, width 8.4 – 9.6 µm. Axial area narrow, only slightly widened towards the central area. Central area forming a large bowtie-shaped fascia. Raphe filiform with slightly curved branches and straight to slightly deflected central endings bearing simple raphe pores. Distal raphe fissures, bent to one side. Striae in the valve middle curved, moderately to strongly radiate, becoming parallel to weakly convergent near the apices, 13 – 15 in 10 µm. Shortened striae sometimes present near the central area. Longitudinal lines absent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF86924942EBFF45FE7B9067.taxon	materials_examined	Type: — Byers Peninsula, Livingston Island, South Shetland Islands, sample BY 066, leg. B. Van de Vijver, coll. date 18 / 01 / 2009, slide no. BR- 4260 (holotype BR), slide PLP- 205 (isotype University of Antwerp, Belgium), slide ZU 8 / 18 (isotype BRM).	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF86924942EBFF45FE7B9067.taxon	biology_ecology	Habitat and Distribution: — Pinnularia australoglobiceps is uncommon on Livingston Island and is mainly found in aquatic habitats. The type population was observed in a small lake near the southern beaches. The lake had an almost circumneutral pH (7.2) with a low specific conductance value (104 µ S / cm). Occasionally, the species was found on wet soil and among mosses around streams and lakes, probably dispersed by wind or water sprays.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF86924942EBFF45FE7B9067.taxon	etymology	Etymology: — The specific epithet refers to the geographic distribution of the species (Latin ‘ australis ’ meaning southern) and its similarity to Pinnularia globiceps.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF86924942EBFF45FE7B9067.taxon	discussion	Observations: — The species most similar to P. australoglobiceps are P. globiceps Gregory (1856: 10), P. iatriaensis Foged (1970: 169), P. lundii Hustedt (1954: 474) and P. bottnica. Pinnularia globiceps has a lower valve width (5.0 – 7.5 µm vs 8.4 – 9.6 µm) with larger capitate ends, usually as wide as the valve middle or only slightly narrower (Krammer 2000). The northern hemisphere species P. iatriaensis has a linear (and not an elliptic-lanceolate) valve outline with slightly undulating (and not convex) margins and a coarser striation pattern with 11 – 12 (vs. 13 – 15) striae in 10 µm (Foged 1970, Krammer 2000). Moreover, the central area in P. iatriaensis is smaller than in P. australoglobiceps. Pinnularia lundii has typically capitate, well set-off apices, contrary to P. australoglobiceps and is usually much longer (40 – 60 µm vs. 25 – 37 µm). Pinnularia bottnica, known from the coast of northern Baltic Sea has a similar striation pattern and central area but a different valve outline with only weakly protracted and obtusely rounded valve ends. In Van de Vijver et al. (2002), valves identified as P. bottnica with similarities to P. globiceps, (see plate 102, Figs 12 – 15) are probably conspecific but have somewhat shorter apices. Pinnularia austroshetlandica possess a similar raphe structure and striation pattern but has narrower, shorter and clearly rostrate ends. Carlson described the species Caloneis austrogeorgica Carlson (1913: 12) from South Georgia. Since type material has yet been located, only one drawing and a rather short description are available for comparison with P. australoglobiceps. The valve dimensions given for C. austrogeorgica are somewhat higher, especially the valve width, an important morphological character; this is almost 1 / 5 higher in the latter (12 µm vs. 8.4 – 9.6 µm in P. australoglobiceps). Until type material has been found and investigated, both species are considered independent.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF80924942EBF8A9FD8296F6.taxon	description	Valves linear with strictly parallel margins and broadly rounded, non-protracted apices. Valve dimensions (n = 20): length 43 – 52 µm, width 7.3 – 8.8 µm. Axial area moderately broad, linear to linear-lanceolate, not, or only very slightly, widening towards the central area. Central area forming a rectangular, usually asymmetrical fascia. Raphe lateral with deflected proximal raphe endings terminating in weakly expanded pores. Distal raphe fissures bayonet-shaped. Striae almost parallel throughout the entire valve. Longitudinal lines absent. One single row of small spines visible on the primary side, 9 – 10 in 10 µm. Valves usually found in pairs, connected by linking spines, lying in juxtaposition. Habitat: — Pinnularia gemella was found in several larger lakes on the central plateau of Byers Peninsula. All lakes had a pH varying between 7.2 and 7.5 and a very low specific conductance level (<60 µS / cm). The species seems to be absent from Hurd Peninsula. Observations: — Pinnularia gemella cannot be mistaken with any other species of Pinnularia due to the presence of the spines on the primary side. Only a few Pinnularia species have spines or form colonies in juxtaposition. Van de Vijver et al. (2004 a, 2009) reviewed all colony- and / or spine-forming species of Pinnularia. Pinnularia subantarctica var. elongata has a similar valve outline but higher stria density and lacks the typical spines of P. gemella. Pinnularia subantarctica var. elongata (Manguin in Bourrelly & Manguin) Van de Vijver & Le Cohu in Van de Vijver, Frenot & Beyens (Figs 206 – 217) Valves linear to weakly linear-lanceolate with parallel to weakly convex valve margins and broadly rounded, subrostrate apices. Valve dimensions (n = 25): length 27 – 59 µm, valve breadth 5.4 – 7.9 µm. Axial area narrow, near the centre weakly deltoid. Central area forming a broad almost rectangular, sometimes asymmetrical, fascia. Raphe slightly lateral with expanded and weakly deflected central pores. Terminal raphe fissures “? ” - shaped. Striae slightly to moderately radiate in the middle, becoming convergent towards the apices, 14 – 15 in 10 µm. Longitudinal lines clearly present. Habitat: — Pinnularia subantarctica var. elongata was most abundant among wet mosses in areas close to the sea and in larger lakes, usually near the shoreline where the presence of animals was clearly visible. PH ranges from 6.9 to 8.4 with a specific conductance varying from 34 to almost 250 µS / cm. Observations: — Pinnularia subantarctica var. elongata is one of the smallest Pinnularia taxa presenting a longitudinal line running across its striae due to the partly internal covering of the striae, leaving only a small opening. It cannot be confused with other species. Pinnularia microstauron has a unique valve outline with more rostrate apices and clearly convex margins.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF80924942EBF8A9FD8296F6.taxon	description	Habitat: — Pinnularia gemella was found in several larger lakes on the central plateau of Byers Peninsula. All lakes had a pH varying between 7.2 and 7.5 and a very low specific conductance level (<60 µS / cm). The species seems to be absent from Hurd Peninsula. Observations: — Pinnularia gemella cannot be mistaken with any other species of Pinnularia due to the presence of the spines on the primary side. Only a few Pinnularia species have spines or form colonies in juxtaposition. Van de Vijver et al. (2004 a, 2009) reviewed all colony- and / or spine-forming species of Pinnularia. Pinnularia subantarctica var. elongata has a similar valve outline but higher stria density and lacks the typical spines of P. gemella. Pinnularia subantarctica var. elongata (Manguin in Bourrelly & Manguin) Van de Vijver & Le Cohu in Van de Vijver, Frenot & Beyens (Figs 206 – 217) Valves linear to weakly linear-lanceolate with parallel to weakly convex valve margins and broadly rounded, subrostrate apices. Valve dimensions (n = 25): length 27 – 59 µm, valve breadth 5.4 – 7.9 µm. Axial area narrow, near the centre weakly deltoid. Central area forming a broad almost rectangular, sometimes asymmetrical, fascia. Raphe slightly lateral with expanded and weakly deflected central pores. Terminal raphe fissures “? ” - shaped. Striae slightly to moderately radiate in the middle, becoming convergent towards the apices, 14 – 15 in 10 µm. Longitudinal lines clearly present. Habitat: — Pinnularia subantarctica var. elongata was most abundant among wet mosses in areas close to the sea and in larger lakes, usually near the shoreline where the presence of animals was clearly visible. PH ranges from 6.9 to 8.4 with a specific conductance varying from 34 to almost 250 µS / cm. Observations: — Pinnularia subantarctica var. elongata is one of the smallest Pinnularia taxa presenting a longitudinal line running across its striae due to the partly internal covering of the striae, leaving only a small opening. It cannot be confused with other species. Pinnularia microstauron has a unique valve outline with more rostrate apices and clearly convex margins.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF80924942EBF8A9FD8296F6.taxon	discussion	Observations: — Pinnularia gemella cannot be mistaken with any other species of Pinnularia due to the presence of the spines on the primary side. Only a few Pinnularia species have spines or form colonies in juxtaposition. Van de Vijver et al. (2004 a, 2009) reviewed all colony- and / or spine-forming species of Pinnularia. Pinnularia subantarctica var. elongata has a similar valve outline but higher stria density and lacks the typical spines of P. gemella.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF80924942EBF8A9FD8296F6.taxon	description	Valves linear to weakly linear-lanceolate with parallel to weakly convex valve margins and broadly rounded, subrostrate apices. Valve dimensions (n = 25): length 27 – 59 µm, valve breadth 5.4 – 7.9 µm. Axial area narrow, near the centre weakly deltoid. Central area forming a broad almost rectangular, sometimes asymmetrical, fascia. Raphe slightly lateral with expanded and weakly deflected central pores. Terminal raphe fissures “? ” - shaped. Striae slightly to moderately radiate in the middle, becoming convergent towards the apices, 14 – 15 in 10 µm. Longitudinal lines clearly present. Habitat: — Pinnularia subantarctica var. elongata was most abundant among wet mosses in areas close to the sea and in larger lakes, usually near the shoreline where the presence of animals was clearly visible. PH ranges from 6.9 to 8.4 with a specific conductance varying from 34 to almost 250 µS / cm.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF80924942EBF8A9FD8296F6.taxon	discussion	Observations: — Pinnularia subantarctica var. elongata is one of the smallest Pinnularia taxa presenting a longitudinal line running across its striae due to the partly internal covering of the striae, leaving only a small opening. It cannot be confused with other species. Pinnularia microstauron has a unique valve outline with more rostrate apices and clearly convex margins.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF80924842EBFD1AFCDF922B.taxon	description	Valves linear to weakly linear-lanceolate with parallel to weakly convex valve margins and broadly rounded, subrostrate apices. Valve dimensions (n = 25): length 27 – 59 µm, valve breadth 5.4 – 7.9 µm. Axial area narrow, near the centre weakly deltoid. Central area forming a broad almost rectangular, sometimes asymmetrical, fascia. Raphe slightly lateral with expanded and weakly deflected central pores. Terminal raphe fissures “? ” - shaped. Striae slightly to moderately radiate in the middle, becoming convergent towards the apices, 14 – 15 in 10 µm. Longitudinal lines clearly present. Habitat: — Pinnularia subantarctica var. elongata was most abundant among wet mosses in areas close to the sea and in larger lakes, usually near the shoreline where the presence of animals was clearly visible. PH ranges from 6.9 to 8.4 with a specific conductance varying from 34 to almost 250 µS / cm.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
03F2686FFF80924842EBFD1AFCDF922B.taxon	discussion	Observations: — Pinnularia subantarctica var. elongata is one of the smallest Pinnularia taxa presenting a longitudinal line running across its striae due to the partly internal covering of the striae, leaving only a small opening. It cannot be confused with other species. Pinnularia microstauron has a unique valve outline with more rostrate apices and clearly convex margins.	en	Zidarova, Ralitsa, Kopalová, Kateŕina, Vijver, Bart Van De (2012): The genus Pinnularia (Bacillariophyta) excluding the section Distantes on Livingston Island (South Shetland Islands) with the description of twelve new taxa. Phytotaxa 44: 11-37, DOI: 10.11646/phytotaxa.44.1.2, URL: https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.44.1.2
