taxonID	type	description	language	source
557C03465E6FFF92FF7FFF497A17FC4D.taxon	type_taxon	Type: Oxalis riparia Norlind (designated by Lourteig 2000: 297).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E6FFF92FF7FFF497A17FC4D.taxon	description	Description: — Herbs or subshrubs, stem erect, decumbent, scandent or stoloniferous. Stem up to ca. 30 cm, more than 1 m long when stoloniferous; internodes 0.1 – 12 cm long, hairs in general with two sizes: (0.1 – 0.5 mm and 0.5 – 2 mm), straight or curved, glandular hairs at least in the flowers. Stipules connate to the petiole or absent; petioles 0.7 – 30.5 cm long; pulvina 0.3 – 2 mm long. Leaf blades 0.4 – 7.6 × 0.4 – 4.1 cm, chartaceous or membranous, depressed obovate to obovate, widely rhombic to rhombic, or widely depressed obtrullate to very widely obtrullate, base cuneate, apex retuse, truncate or acute, sometimes mucronulate. Dichasia with 2 – 13 - flowers; peduncle 0.5 – 18 cm long; bracts lanceolate. Sepals with the base rounded, apex acute; petals 6.5 – 23 mm long, yellowish, spatulate, the apex crenate-denticulate, adaxially with abundant glandular hairs; shorter stamens glabrous, longer ones with ascending hairs, anthers rimose; pistil with ascending, abundant hairs, stigmas papillose. Capsules 2 – 7 (10) × 3 – 15 mm, depressed ovoid to ovoid, 5 - lobed; seeds 1 – 3 (5) per locule, (1.6) 2.1 – 3.8 × 1 – 2.4 mm, ellipsoid, widely ellipsoid or obovoid, rounded at the base, with apex acute; seed surface longitudinally crested, with almost echinate or pustulate projections.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E6FFF92FF7FFF497A17FC4D.taxon	distribution	Distribution and habitat: — Oxalis sect. Ripariae is distributed in northern Argentina, extending south to La Pampa and west to Tucumán provinces, southern Paraguay, Uruguay, and southern Brazil, with a single species (O. riparia) extending northwards along the Mantiqueira range in southeastern Brazil (fig. 4). Mostly distributed in the Pampa and Atlantic Forest phytogeographic domains, with few collections in the Argentinian Chaco and Piedmont Andean forests, from sea level (O. pampeana) to ca. 1,770 m elevation (O. sarmentosa). The species preferred habitats are Araucaria forest and trail edges, rural roadsides, grasslands, slopes and river margins. Species richness: — 11 species in the present account (Table 2).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E60FF9CFF7FFCE27C52F7DE.taxon	materials_examined	Type (lectotype designated here): — PARAGUAY. Caaguazú: dans les campos, 12 November 1874, B. Balansa 2242 (P 02440123!, image of the lectotype available at https: // science. mnhn. fr / institution / mnhn / collection / p / item / p 02440123; isolectotypes at BR 0000005286904!, G fide Lourteig, GOET fide Lourteig, K fide Lourteig, P 02440124!, P 02440125!, SR 8311!) (figs. 5 – 6).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E60FF9CFF7FFCE27C52F7DE.taxon	description	Decumbent subshrub. Stem slender, up to ca. 60 cm long, branching from the base, decumbent, densely covered with leaves; shorter hairs ca. 0.4 mm long, curved or appressed, very abundant; longer hairs ca. 1 mm long, ascending and patent, abundant; glandular hairs ca. 0.5 mm long, sparse; internodes 0.4 – 1.3 cm long. Stipules ca. 1.1 × 2 mm, semicircular, the apex connate to the petiole, hairs like on stem; petioles 2.2 – 9.5 cm long, pulvina ca. 1 mm long. Leaf blades 7 – 18 × 4 – 13 mm, coriaceous, widely obovate to obovate, discolorous, with base cuneate, margin revolute, apex truncate to rounded, sometimes mucronulate; shorter hairs ca. 0.4 mm long, curved or appressed, abundant adaxially, very abundant abaxially; longer hairs 1 – 2 mm long, ascending and patent, moderate adaxially, abundant abaxially; glandular hairs ca. 0.5 mm long, occasional adaxially, sparse abaxially. Dichasia with 5 flowers, as long as the leaves; peduncle 1.5 – 6.1 cm long; bracts 1 – 2.5 × 0.2 mm, lanceolate; shorter hairs ca. 0.2 mm long, ascending, abundant; longer hairs ca. 1 mm long, patent, moderate, reddish; bracts 1 – 2.5 × ca. 0.2 mm, lanceolate; bracteoles ca. 1.1 × 0.2 mm, lanceolate. Pedicels 5 – 8 mm long; sepals 4 – 5.5 × 0.75 – 1 mm, base rounded, apex acute, hairs ca. 1 mm long, ascending, simple and glandular, very abundant; petals yellow, 6.6 – 8 mm long, spatulate, with apex crenatedenticulate, adaxially with glandular hairs; the shorter stamens ca. 2 mm long, glabrous, the longer ones ca. 4 mm long, hairs ascending; mid-styled pistil, ca. 5 mm long, with abundant, ascending hairs, stigmas papillose. Capsules 2.6 – 4 × 4.7 – 5.7 mm, depressed ovoid, 5 - lobed, hairs ca. 2 mm long, patent, very abundant. Seeds 1 per locule, ca. 2 × 1.5 mm (immature), widely elliptic to elliptic, with rounded base and acute apex.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E60FF9CFF7FFCE27C52F7DE.taxon	distribution	Distribution and habitat: — Endemic to Paraguay and known only for the municipality of Caaguazú (Caaguazú Departament), and near Pira Pytá river (Alto Paraná Departament) (fig. 6). It grows in grasslands and in the margin of seasonally dry forests.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E60FF9CFF7FFCE27C52F7DE.taxon	biology_ecology	Phenology: — Flowers and fruits have been collected in September and October.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E60FF9CFF7FFCE27C52F7DE.taxon	conservation	Conservation status: — The only record of this species at Caaguazú Department dates 12 November 1874. Between 1989 and 1990, Oxalis benjaminii was found about 150 km far from this locality, in Alto Paraná. The species has not been recorded in protected areas and the only known records are from areas of extensive agriculture and cattle farming, including the type-locality, which has suffered deforestation since 1970 and is now an urban area. The AOO of this species is 8 km ², with an inferred decline in extent and habitat quality, thus recommended as Critically Endangered (CR) applying the criterion B 2 a, b (iii).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E60FF9CFF7FFCE27C52F7DE.taxon	discussion	Typification of Oxalis benjaminii: — Lourteig (2000) described Oxalis benjaminii citing six specimens of Balansa 2242 [BR, G, GOET, K, P (2 specimens)]. Between the two specimens at P, she indicated one as the “ holotype ” and the other as an “ isotype ”, but she did not provide any means to distinguish these two specimens, so they are regarded as syntypes (cf. Art. 40.2 of ICN). We located three samples of B. Balansa 2242 at P (barcodes P 02440123, P 02440124, and P 02440125), all of which were identified by Lourteig. Among these, the material selected as the lectotype (P 02440123) is the one with fruits and floral remains, and which best represents its habit, with more spacely arranged leaves. Taxonomic notes: — This species can be easily recognized by small obovate to widely obovate and strongly discolorous leaflets, with a whitish abaxial surface due to dense hair-covering. Leaves have an helicoidal arrangement and leaflets are caducous, leaving persistent petioles. It is morphologically similar to Oxalis paranaensis, from which it can be distinguished by the decumbent stem, branching from the base (vs. procumbent, non-branched stems in O. paranaensis), and the 2 – 5 - flowered (vs. 1 – 3 - flowered) inflorescences. Moreover, the river basin where Oxalis benjaminii occurs drains to Paraná river, and is about 700 km away from the locality where O. paranaensis is found, which drains to the Iguaçu river.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E60FF9CFF7FFCE27C52F7DE.taxon	materials_examined	Specimens examined: — PARAGUAY. Alto Paraná: Zona rio Pira Pyta, 20 September 1989, G. C. Marmoni 1611 (CTES); Estancia Santa Elena, 11 October 1990, A. Schinini & G. C. Marmori 27218 (CTES, FLOR, P).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E62FF9EFF7FFF237C79FCEA.taxon	description	Stoloniferous herb. Stem slender, up to ca. 60 cm long (150 cm in literature), reddish; shorter hairs ca. 0.1 mm long, patent, very thin, moderate to abundant; longer hairs 0.5 – 1 (1.5) mm long, ascending, patent and descending, sparse to moderate (very abundant on young parts); sparse glandular hairs ca. 0.5 mm long; internodes 0.1 – 8.5 cm long, alternating between very short and long internodes, nodes rooting. Stipules 3 – 5 × 2 – 3 mm, semicircular, the apex connate to the petiole, hairs like on stem; petioles 4 – 12 cm long, pulvina ca. 1 mm long, hairs 1 – 2 mm long, patent, abundant. Leaf blades 0.8 – 3.8 × 0.8 – 2.7 cm, coriaceous, widely depressed obovate to very widely obovate, rarely widely obovate, discolorous, with the base cuneate, the margin entire, with abundant, ascending hairs ca. 1 mm long; with the apex obtuse to rounded, or retuse; shorter hairs ca. 0.2 mm long, curved or appressed to ascending, sparse to moderate adaxially, abundant abaxially; longer hairs ca. 1 – 2 mm long, appressed, sparse to moderate adaxially, moderate to abundant abaxially; glandular hairs ca. 0.5 mm, sparse abaxially. Dichasia with 13 flowers, as short as the leaves; peduncle 0.5 – 4.7 cm long; shorter hairs 0.1 – 0.2 mm long, appressed to ascending and descending, abundant, sometimes curved; longer hairs 1 – 2.5 mm long, patent, moderate to abundant; glandular hairs ca. 1 mm long, occasional; bracts 1 – 2.5 × 0.2 – 0.5 mm, lanceolate; bracteoles 0.5 – 1 × 0.2 mm, lanceolate. Pedicels 0.3 – 2 mm long; sepals 3 – 4 × 1 mm, base rounded, apex acute, shorter hairs ca. 0.2 mm long, moderate, longer hairs 0.5 – 1 mm long, appressed to ascending, moderate, glandular hairs ca. 0.5 mm long, occasional; petals yellow, 6 – 10 mm long, spatulate, crenate-denticulate at the apex, adaxially with sparse glandular hairs; shorter stamens ca. 3 mm long, glabrous, longer ca. 5 mm long, hairs ascending; pistil ca. 6 mm long, hairs ascending, abundant, stigmas papillose. Capsules 3 – 6 × 3 – 4 mm, very widely ovoid, 5 - lobed, hairs ca. 0.5 mm long, ascending, moderate. Seeds 1 per locule, 1.6 – 3.2 × 1 – 1.9 mm, elliptic, with rounded base and acute apex.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E62FF9EFF7FFF237C79FCEA.taxon	distribution	Distribution and habitat: — This species has been collected in Brazil (Paraná state) and Argentina (Missiones province), always in shady habitats within forests or forest edges. Phenology: — Flowers and fruits have been collected from October to January. Conservation status: — Oxalis bifrons is known from four localities at western Paraná state (Brazil) and the Missiones province in Argentina. It is associated to Araucaria forests, which have been historically explored for logging and remains with less than 1 % of its original cover in good conservation status. This species has not been recorded in protected areas and its sampling spots are immersed within and extensive agricultural matrix. Due to its EOO = 7,382 km ² and AOO = 16 km ², with an inferred decline in area extent and habitat quality due to advance of agricultural activities and urbanization, we recommend to categorize it as Endangered [EN B 2 a, b (iii)]. Nomenclatural notes: — Oxalis bifrons was described by Progel (1877: 495) based on a Sellow’s collection. Lourteig (1983, 2000) suggested that this sample was deposited at B and that it was presumably destroyed during World War II (Hiepko 1987). This specimen was considered to be collected at Montevideo (Uruguay) by Progel (l. c.), but it is very likely that this locality was wrongly attributed, as there are no other samples of this species from Uruguay. Argentinean samples are rare. We agree with Lourteig (1983, 2000) that this collection is likely from Brazil, without precise locality indication. Taxonomic notes: — Oxalis bifrons differs from O. sarmentosa mostly by the rounded (vs. acute) leaflet apex, and the blade wider above (vs. below) the mid portion. The indumentum also differs, as in Oxalis bifrons leaflet abaxial surface bears more shorter and curved hairs 0.1 – 0.2 mm long and longer ones 1 – 2 mm long, while in O. sarmentosa leaf abaxial surface is glabrous or with shorter straight hairs 0.2 – 0.5 mm long and longer ones 1 (– 2) mm long. Oxalis bifrons is also similar to O. pampeana, from which it can be distinguished by leaflets with sparse to abundant hairs not covering the blades (vs. blades entirely covered by the indumentum). The two species are allopatric, as O. bifrons is restricted to western Paraná and northeastern Argentina, while O. pampeana occurs exclusively in Rio Grande do Sul coastal plains and (rarely) in the western part of the same state. Specimens examined: — ARGENTINA. Missiones: San Pedro [as Gral. M. Belgrano], al sur de Bdo. de Irigoyen, 26 ° 18 ’ 30,9 ’’ S, 53 ° 39 ’ 53,8 ’’ W, 6 January 2011, H. A. Keller & M. M. Franco 9378 (CTES); H. A. Keller & M. M. Franco 9411 (CTES); BRAZIL. Paraná: Cantagalo, sítio Cachoeira, 17 September 2009, J. M. Silva et al. 7361 (MBM, RB); Laranjeiras do Sul, 21 October 1969, G. Hatschbach 22581 (CTES, MBM, NY 00470357 [web], NY 00470358 [web], P, UEC 002860 [web]); Rincão Grande, 12 October 1974, G. Hatschbach 35209 (MBM, P); Roncador, 19 December 1973, G. Hatschbach 32897 (CTES, MBM, NY 00470358 [web], P, RB 223184 [web], US 01853527 [web]).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E64FF9BFF7FFF237B0FFE2F.taxon	description	Decumbent subshrub. Stem up to ca. 20 cm long, tuberose stem up to ca. 3 × 8 cm, lateral aerial branches prostrate; shorter hairs 0.1 – 0.2 mm long, patent or curved, sparse to abundant; longer hairs 0.5 – 2 mm long, ascending, patent and descending, abundant, yellowish; glandular hairs ca. 0.5 mm long, occasional throughout; internodes 1 – 2.1 cm long. Stipules ca. 2 × 1 mm, rectangular, connate to the petiole, hairs ca. 1 mm long; petiole ca. 1 – 5 cm long, pulvina ca. 0.2 mm long. Leaf blades 9 – 25 × 9 – 26 mm, coriaceous, widely depressed obovate to very widely obovate, slightly discolorous, the base cuneate, the apex retuse to obcordate; shorter hairs ca. 1 mm long, appressed, sparse adaxially, moderate abaxially; longer hairs ca. 2 mm long, appressed, moderate in both surfaces; glandular hairs ca. 1 mm long, occasional abaxially. Dichasia with up to 4 flowers, as long as the leaves; peduncle 0.5 – 2 cm long; hairs as in stem; glandular hairs moderate; bracts ca. 1.5 × 2 mm, lanceolate, hairs ca. 3 mm long; bracteoles ca. 2 × 0.5 mm, lanceolate. Pedicels 1 – 10 mm long; sepals 3 – 6 × 0.8 – 1.2 mm, base rounded, apex acute, hairs ca. 1 mm long, simple and glandular, moderate, ascending; petals yellow, 11 – 23 mm long, spatulate, the apex crenate-denticulate, occasionally reddish, adaxially with glandular hairs sparse to moderate; shorter stamens ca. 4 mm long, glabrous, longer ca. 6 mm long, hairs ascending; pistil ca. 10 mm long, hairs ascending, abundant, stigmas papillose. Capsules 4 × 8 mm, depressed ovoid, 5 - lobed, hairs ca. 2 mm long, patent, abundant, rigid. Seeds 1 per locule, 2.6 – 3.8 × 1.7 – 2.5 mm, elliptic, the base rounded, the apex acute.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E64FF9BFF7FFF237B0FFE2F.taxon	distribution	Distribution and habitat: — This species is associated to the Pampas biome at Argentina, Brazil, and Uruguay, with occasional occurrences in seasonally dry forests (Atlantic Forest biome) at western Rio Grande do sul state in Brazil (fig. 6). Its distribuition is sparse in open areas, such as grasslands, ravines or among rocks at full sun. Populations of Oxalis eriocarpa are commonly observed in grasslands after burning, due to resprouting from underground stems.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E64FF9BFF7FFF237B0FFE2F.taxon	biology_ecology	Phenology: — Flowers and fruits have been collected from August to January.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E64FF9BFF7FFF237B0FFE2F.taxon	conservation	Conservation status: — Oxalis eriocarpa is widespread in Rio Grande do Sul state, northeastern Argentina and Uruguay (EOO = 383,989 km ²), however its distribution is discontinuous, and the populations comprise in total an Area of Occupancy of ca. 220 km ². Despite its resilience to fire, this species does not tolerate long shading periods or intensive soil conversion for agriculture. Few areas of the Pampa biome area protected (Overbeck et al. 2015), and there is a single record of this species in a protected area (Saint-Hilaire Municipal Natural Park, Rio Grande do Sul, Brazil). Because the habitat where O. eriocarpa grows has good connectivity, we propose a conservative status of Near Threatened (NT).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E64FF9BFF7FFF237B0FFE2F.taxon	discussion	Typification of Trifolium magellanicum: — In the protologue, Poiret annotated: “ croit au détroit de Magellan, où elle eté decouverte par Commerson (V. S. in herb. LAM) ”, indicating that he analyzed a dried specimen collected by Commerson, probably in the Magellan Strait. Lourteig (1983) indicated the specimen at P-LAM as the lectotype (P 00295091); additional samples at P-Jussieu, and in the general collection of P and FI are thus isolectotypes. Poiret recognized the fact that the material did not fit properly in Trifolium L. Afterwards, Candolle (1825) placed the species in Oxalis and commented that label information point to Montevideo as the type locality, not “ Magellan ”. Taxonomic notes: — Oxalis eriocarpa can be easily recognized among the other species of the section by leaflets with the apex retuse to obcordate, and because they are entirely covered by long and stiff hairs ca. 2 mm long. It is also the species of the section with the largest flowers (up to ca. 23 mm long) with vivid yellow corolla, reddish on nectar guides and, sometimes, petals margins (figs. 8 b-c).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E64FF9BFF7FFF237B0FFE2F.taxon	materials_examined	Specimens examined: — ARGENTINA. Corrientes: Ituizaingó, Rincón Ombú Chico, 17 November 1978, M. M. Arbo et al. 2102 (CTES); 15 km E de ruta nacional nº 12, estrada a San Carlos, 13 November 1971, A. Krapovickas et al. 17996 (CTES); Predio Santo Domingo, 20 May 2008, H. A. Keller et al. 5522 (CTES); 20 km W de San Carlos, 9 September 1974, C. L. Cristóbal & A. Krapovickas 1726 (CTES); Paso de los libres, Laguna Mansa, 21 September 1974, A. Schinini et al. 7229 (CTES); 3 cerros, Co. de Susini, 16 September 1974, A. Schinini et al. 18539 (CTES, MBM); Santo Tomé, Estancia Garruchos, 13 November, E. R. Guaglianone 97 (SI); Ruta 40, 8 km NE de Santo Tome, 29 July 1974, M. Dematteis et al. 714 (CTES); Ayo. Chimiray, 23 September 1974, A. Krapovickas et al. 26137 (CTES); Garruchos, 9 October 1974, A. Schinini & O. Ahumada 20760 (CTES); Colonia Garabi, 21 September 1974, A. Krapovickas et al. 25964 (CTES); 31 October 1974, A. Krapovickas & C. L. Cristóbal 16408 (CTES). Entre Rios: Concordia, De San Salvador a Concordia, 18 October 1974, N. S. Troncoso et al. 1984 (CTES). Misiones: Apostoles, Cruce rutas 201 - 203, 30 km NE de Apóstoles, 22 September 1974, A. Krapovickas et al. 15461 (CTES); Candelaria, Santa Ana, 14 September 1912, F. M. Rodríguez 586 (SI); Posadas, 15 September 1912, C. Schrottky 203 (SI); Leandro N. Alem, Ruta 14, General Güemes, 22 October, A. L. Cabrera 29329 (SI); Santa Ana, 1 November 1974, M. Crovetto 9682 (CTES). BRAZIL. Rio Grande do Sul: Júlio de Castilhos, 28 October 2016, A. Nuernberg et al. 1830 (FLOR); Pelotas, 26 August 1974, J. S. C. Sacco 228 (CTES, P); Pinheiro Machado, Cox. Pedras Altas, 11 November 1974, T. M. Pedersen 11441 (CTES, P); Santo Angelo, Granja Piratini, 23 September 1974, K. Hagelund. 10485 (CTES); São Francisco de Assis, 28 October 2016, A. Nuernberg et al. 1824 (FLOR); São Gabriel, BR 290, some 20 km E of Rosário do Sul, 9 November 1974, T. M. Pedersen 11408 (CTES, P); Viamão, Parque Saint-Hilaire, A. Nuernberg 1820 (FLOR). URUGUAY. Maldonado: Ruta 60, km 37, 14 November 1974, J. M. Bonifacio et al. 1820 (CTES); Rivera, Ayo. Curticera, Ruta 5, km 491, 30 ° 58 ’ 45 ’’ S, 55 ° 34 ’ 31 ’’ W, 12 December 1997, S. Neffa et al. 464 (CTES); Tacuarembó, Camino a Gruta de los Cuervos, esculea “ Capón de la Yerba ”, 31 ° 36 ’ 50 ’’ S, 56 ° 03 ’ 17 ’’ W, 214 msm, 17 November 2007, S. Neffa 2068 (CTES).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E66FF9BFF7FFDBB7DE7F7DB.taxon	description	Stoloniferous herb. Stem slender, up to ca. 70 cm long, reddish, glabrous or with hairs ca. 0.1 mm long, patent, occasional; internodes 1.5 – 10.2 cm long, nodes radicant. Stipules ca. 3.5 × 2 mm, semicircular, connate to the petiole, hairs ca. 1 mm long, sparse, purplish; petioles 5 – 28 cm long; shorter hairs ca. 0.1 mm long, patent, moderate to abundant; longer hairs ca. 0.6 mm long, patent, occasional, with apex purplish; pulvina ca. 1 mm long, hair ca. 1 mm long, patent, moderate. Leaf blades 1.1 – 3.1 × 1.2 – 3.1 cm, coriaceous, widely depressed obovate to very widely obovate, discolorous, adaxial surface dark green, abaxial purplish, the base cuneate, the apex rounded or truncate, sometimes retuse, glabrescent; shorter hairs ca. 0.1 mm long, appressed, occasional on both surfaces; longer hairs ca. 0.5 mm long, appressed, sparse along veins on both surfaces, abundant at margin. Dichasia with 8 flowers, shorter than the leaves; peduncle 1 – 6.7 (11) cm long; shorter hairs ca. 0.1 mm long, patent, moderate to abundant; longer and glandular hairs ca. 0.5 mm long, patent, occasional; bracts 1 – 4 × 0.5 – 1 mm, lanceolate, hairs ca. 0.3 mm long, patent, sparse; bracteoles 1 – 2 × 0.3 – 0.5 mm, lanceolate. Pedicels 1 – 14 mm long; sepals 3 – 4 × 1 mm, reddish, base rounded, apex acute, short hairs ca. 0.1 mm long, moderate to abundant, longer and glandular ca. 0.3 mm long, patent, occasional to sparse; petals yellow, 9 – 11 mm long, spatulate, the apex crenate-denticulate, adaxially with glandular hairs sparse; shorter stamens ca. 4 mm long, glabrous, longer hairs ca. 6 mm long, hairs ascending; mid-styled pistil ca. 5 mm long, hairs ascending, abundant, stigmas papillose. Capsules 4 – 5 (6) × 4 – 5 mm., very widely ovoid, 5 - lobed, hairs ca. 1 mm long, ascending and patent, abundant. Seeds 1 per locule, ca. 2.9 × 2.1 mm, widely elliptic to elliptic, the base rounded, the apex acute, surface crested.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E66FF9BFF7FFDBB7DE7F7DB.taxon	distribution	Distribution and habitat: — This species is endemic to Curitiba area, where it is always associated to forests dominated by Araucaria angustifolia (Bertol.) Kuntze, regarded as mixed ombrophilous forests (IBGE 2012). Phenology: — Flowers and fruits have been collected from September to December. Conservation status: — The habitat of the species is severly threatened, because Araucaria forests remain in good state of conservation for about only 1 % of its original cover. It has been historically sampled in four localities in the surroundings of Curitiba (Paraná state), but at least one of these was probably extinct due to recent urban expansion. It has never been recorded at protected areas. Due to its EOO = 581 km ² and AOO = 16 km ², with the original habitat severely fragmented, and with an observed decline in extent of occurrence and habitat quality, we recommend its categorization as Endangered [EN B 1 B 2 a, b (iii)]. Nomenclatural notes: — Norlind (1915: 14) originally reported two gatherings, i. e. Dusén 7073 and 7140. Lourteig (1983: 51) carried out a lectotypification indicating Dusén 7073 as the “ holotype ” (Art. 9.10) (she did not mention the collection Dusén 7140). We traced four specimens of Dusén 7073, three at S (S-R- 9771, S- 13 - 11602, S- 13 - 11603) and one at K (K 000531580) (cf. Art. 9.22). To narrow the choice to a single specimen, a second-step typification is proposed following Art. 9.17 of ICN. The specimen S-R 9771 fits unequivocally the original description and was selected as the second-step lectotype for bearing the best-preserved branch, with leaves of different sizes. Taxonomic notes: — Oxalis hepatica is similar to Oxalis bifrons, from which it can be distinguished by being glabrescent plants (vs. with moderate hairs in O. bifrons), with up to 8 - flowered (vs. up to 13 - flowered) inflorescences and leaflets with the abaxial surface purplish (vs. light green in O. bifrons). Specimens examined: — BRAZIL. Paraná: Araucária, 12 August 1951, L. Camargo s. n. (SP 56306); Curitiba, Bacacheri, 13 October 1970, G. Hatschbach 24919 (MBM, P); 2 December 1970, G. Hatschbach 25726 (MBM, P); Tijucas do Sul, Lagoinha, estrada para Saltinho, 2 September 1986, G. Hatschbach 50997 (MBM, MO [web], P, US [web]); 25 ° 55 ’ 2.68 ’’ S, 49 ° 13 ’ 3.65 ’’ W, 30 September 2016, A. Nuernberg et al. 1800 (FLOR).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E67FF84FF7FF98478D6FB72.taxon	diagnosis	Diagnosis: — This new species is similar to Oxalis serpens, from which it can be distinguished by the 1 – 3 - flowered (vs. uniflorous) inflorescences, the glandular hairs (lacking in O. serpens), emarginate (vs. retuse) leaflet apex and by the immersed inconspicuous secondary veins (vs. usually two conspicuous secondary veins abaxially in O. serpens). Oxalis lourteigiana is also similar to O. bifrons, but it differs by the leaflets 0.8 – 1.4 cm long (vs. up to ca. 4 cm long), with an emarginate (vs. obtuse to rounded, sometimes retuse) apex, and immersed inconspicuous secondary veins (vs. secondary veins abaxially conspicuous in O. bifrons). Stoloniferous herb. Stem slender, up to ca. 45 cm long; shorter hairs 0.2 – 0.5 mm long, ascending, patent, descending, sometimes curved, moderate; longer hairs ca. 1 mm long, patent, occasional; glandular hairs ca. 0.5 mm long, patent, moderate; internodes 0.8 – 3.5 cm long, nodes radicant. Stipules 1.5 – 2 × 1 – 1.5 mm, semicircular, connate to the petiole; petioles 1 – 6 cm long; pulvina ca. 1 mm long. Leaf blades 0.8 – 1.4 × 0.85 – 1.32 cm, coriaceous, widely depressed obovate, discolorous, the base cuneate, the apex emarginate; shorter hairs ca. 0.5 mm long, appressed, occasional adaxially, sparse to moderate abaxially; longer hairs ca. 1 mm long, appressed, moderate adaxially, occasional abaxially; glandular hairs 0.5 – 1 mm long, appressed to ascending, sparse adaxially, moderate abaxially; margin with hairs 0.5 – 1 mm long, ascending, moderate. Dichasia with 3 flowers, shorter than the leaves; peduncle 0.5 – 2.7 cm long; shorter hairs ca. 0.2 mm long, ascending, descending, patent or curved, moderate to abundant; longer hairs 0.5 – 0.8 mm long, patent, sparse; glandular hairs ca. 0.5 mm long, patent, sparse to moderate; bracts ca. 1 × 0.2 mm, lanceolate; bracteoles ca. 0.5 × 0.2 mm, lanceolate. Pedicels 3 – 12 mm long; sepals 2.5 – 3.2 × 0.6 – 1 mm, base rounded, apex acute; shorter hairs ca. 0.2 mm long, appressed, moderate; longer hairs 0.5 – 1 mm long, appressed to ascending, moderate; glandular hairs ca. 0.5 mm long, appressed to patent, sparse to moderate; petals yellow, 7 – 8 mm long, spatulate, the apex crenate-denticulate, adaxially with sparse glandular hairs; shorter stamens ca. 3 mm long, glabrous, longer ca. 6 mm long, hairs appressed, moderate to abundant; mid-styled pistil ca. 3.5 mm long, hairs appressed, abundant, stigmas papillose. Capsules ca. 2 × 3 mm, depressed ovoid, 5 - lobed, hairs ca. 0.5 mm long, appressed to patent, moderate, glandular hairs 0.5 – 1 mm long, patent, moderate. Seeds 1 per locule (immature), 2 – 2.5 × 2 – 2.5 mm, circular, the base rounded, the apex acute.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E67FF84FF7FF98478D6FB72.taxon	distribution	Distribution and habitat: — This species is known only from the type collection, presumably collected from gallery forests along the Capivari river at Tibagi, Paraná state. Phenology: — Flowers and fruits were collected in February.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E67FF84FF7FF98478D6FB72.taxon	etymology	Etymology: — This species honors Alicia Lourteig (1913 – 2003), an Argentinian botanist whose life was partially dedicated to the study of Oxalis. Conservation status: — The locality where this species was collected is immersed in a plantation matrix with small fragments of native forest along the Capivari river or in isolated patches among crop fields. It has not been recorded at protected areas and its habitat is severely fragmented and of poor conservation quality, with an AOO of just about 4 km ². We recommend to categorize this species as Critically Endangered following IUCN (2017) categories and criteria [CR B 2 a, b (iii)].	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E79FF81FF7FFB0F799DFC26.taxon	description	Misiones: Pirapitai, October 1892, G. Niederlein 243 d (S-R- 9790 [fragm. From B] image of the lectotype available at https: // plants. jstor. org / stable / viewer / 10.5555 / al. ap. specimen. s-r- 9790). (figs. 11 – 12).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E79FF81FF7FFB0F799DFC26.taxon	distribution	Distribution and habitat: — This is the most common species of Oxalis sect. Ripariae, with a wide distribution in southern Brazil, including São Paulo state (Fiaschi & Conceição 2005), Argentina (López 2017), Paraguay, and Uruguay (fig. 12). It is apparently indifferent to specific soil conditions, and has been collected at forest edges, roadsides, and even sidewalk crevices in large towns. Phenology: — Flowers and fruits have been collected throughout the year. Conservation status: — Due to its wide extent of occurrence and habitat generalism, Oxalis niederleinii should be regarded as of least concern (LC) according with IUCN (2017) categories and criteria. Nomenclatural notes: — Saint-Hilaire (1825) proposed to distinguish “ Oxalis refracta var. α ” (i. e., O. refracta var. refracta) and O. refracta var. debilis. Because the epithet “ debilis ” was occupied by Oxalis debilis R. Knuth, Knuth (1919) decided to propose the replacement name Oxalis niederleinii R. Knuth for recognizing this taxon at the species level (Lourteig 1983, 2000). Typification of Oxalis refracta var. debilis: — Saint-Hilaire (1825) described Oxalis refracta var. debilis with a brief diagnosis and adding “ [inveni in] Decembre in sylvulis humidis umbrosisque ad ripas rivuli dicti Arroio del Rosario, provincial Cisplatina ”. Lourteig (1983) cited two samples from P (Saint-Hilaire C 2 2326) as the “ holotype and isotype ” (actually a lectotypification), but she did not discriminate these two samples. Among three Saint-Hilaire C 2 2326 specimens traced at P, we chose P 02440263 as the second-step lectotype because it bears a complete specimen, with roots and flowers, and fits unequivocally the original description. Typification of Oxalis refracta var. grandiflora: — In the original description of Oxalis refracta var. grandiflora, Briquet (1899: 155) cited “ E. M. Reineck & J. Czermak 32 ”, which was also cited by Knuth (1930), but without indicating the herbarium of deposit. There are two specimens collected by these authors at G: E. M. Reineck & J. Czermak 32 (field no.) (G 00414388; 1 / 2, plus fragment; 2 / 2) and E. M. Reineck & J. Czermak 59 (G 00414387), the latter of which was incorrectly cited as the type by Lourteig (1983). The material chosen here as lectotype follows the protologue and was annotated by Briquet. Taxonomic notes: — Oxalis niederleinii can be easily distinguished from other species of Oxalis sect. Ripariae but may be similar to O. corniculata L. (O. sect. Corniculatae), from which it can be distinguished by the presence (vs. absence) of glandular hairs, and depressed ovoid to ovoid (vs. narrowly ellipsoid) capsules with 1 – 3 seeds 2 – 2.5 × 1 – 1.4 mm per locule (vs. ca. 12 seeds 1.2 – 1.5 × 0.9 – 1 mm per locule). Oxalis niederleinii has several synonyms due to its wide morphological variability. Populations from different localities do not display unique morphological atributes that allow recognition of infraspecific taxa, and the variation appears to be more related to environmental variation throughout its latitudinal distribution. The wide morphological variation of Oxalis niederleinii is specially observed in hairs density (from glabrescent to moderate), type (simple or glandular), and size (0.1 – 1 mm long), and leaflet size (4 – 22 × 6 – 24.6 mm) and shape (from depressed obovate to widely depressed obovate). Specimens examined: — ARGENTINA. Buenos Aires: Isla Martín García, camino a la casa de Bombas, 12 November 1994, J. A. Hurrell 2100 (MBM, RB 00271098 [web], SI); Isla Martín García, camino de Los Alamos, 9 December 1993, J. A. Hurrell 1560 (SI); Corrientes: Curuzú Cuatiá, Estancia Araguá, 2 November 1979, T. M. Pedersen 12519 (CTES, ICN, MBM); Capital, 7 September 1983, A. Schinini 23855 (CTES, RB 00271124 [web]); Santo Tomé, Ayo. Chimiray, 23 September 1974, A. Krapovickas 26133 (CTES); Monte Caseros, Orillas del Timboi, Estancia La Potota, 17 October 1949, E. G. Nicora 4947 (SI); Paso de los Libres, Laguna Mansa, 21 September 1973, A. Schinini 7230 (CTES, RB, RB 00271124 [web]); Entre Ríos: Diamante, 15 May, A. Burkart et al. 25341 (SI); Misiones: Apóstoles, Alrededores del pueblo, 4 September 1985, M. E. Múlgura 373 (SI); Candelaria; Bonpland, s. d. P. Jorgensen 32335 (CTES, RB 00271128 [web]); Eldorado, 9 July 1972, A. Schinini 4875 (CTES); Guaraní, Parque Provincial Moconá, 27 ° 09 ’ S, 53 ° 54 ’ W, 26 February 1995, F. O. Zuloaga 5019 (CTES); Iguazú, Parque Nacional Iguazu, Ruta 101, Ayo. Yacui, 8 August 1995, R. O. Vanni 3400 (CTES); Oberá, 10 August, S. M. Pire 405 (CTES, SI); San Pedro, Ruta Provincial 16, hacia Parque Provincial Esmeralda, 26 ° 40 ’ 07 ’’ S 53 ° 57 ’ 40 ’’ W, 28 November 2004, F. O. Zuloaga 8244 (SI); Tucumán: Chicligasta, Quebrada de las Pavas, puesto Sta. Rosa, 24 March 1953, A. G. Schulz 8409 (SI). BRAZIL. Paraná: Araucária, 25 ° 37 ’ 42.8 ’’ S, 49 ° 27 ’ 21.5 ’’ W, 1 October 2016, A. Nuernberg et al. 1810 (FLOR); Bocaiúva do Sul, Barra Grande, G. Hatschbach 4070 (MBM, P); Colombo, Rio Palmital, 1 January 1973, G. Hatschbach 32808 (CTES, MBM 027680 [web], MO 2574919 [web], MO 1061577 [web]); Foz do Iguaçu, Parque Nacional do Iguaçu, 07 May 1949, A. P. Duarte & E. Pereira 1634 (FLOR, RB); Guarapuava, 27 September 2009, O. S. Ribas et al. 8318 (MBM); Ivaí, Rio Palmital, G. Hatschbach 22367 (MBM, P); Laranjeiras do Sul, Estrada Campo Novo - Pinhal Ralo, J. C. Lindeman et al. 2950 (MBM, NY 00470506 [web], UB); Ponta Grossa, 02 November 1928, F. C. Hoehne s. n. (NY 01096316 [web], P, SP 23335, SPF 00140633 [web]); Rio Branco do Sul, Rod. PR- 092, 10 January 1985, G. Hatschbach 48830 (FLOR, FUEL, MBM, RB); Roncador, Aterrado Alto, G. Hatschbach 32904 (MBM, P); Rio Grande do Sul: Agudo, Morro Agudo, 27 September 1985, D. B. Falkenberg 3333 (FLOR, MBM); Bento Gonçalves, 29 September 1986, F. Vieira s. n. (FLOR 21073); Caçapava do Sul, Parque Nacional do Iguassú, 03 October 1961, E. Pereira 6634 (RB 00652613 [web], UB); São Francisco de Assis, October 2016, A. Nuernberg et al. 1837 (FLOR); São Pedro do Sul, 29 ° 30 ’ S, 54 ° 08 ’ W, 28 October 2016, A. Nuernberg et al. 1828 (FLOR); Santa Catarina: Araranguá, Morro dos Conventos, G. Hatschbach et al. 57867 (MBM, P); Ipira, Rio do Peixe, 16 September 1994, G. Hatschbach et al. 61075 (FLOR, MBM, P); Itapiranga, Linha Coqueiro, 01 January 1964, R. Reitz & R. M. Klein 16821 (CRI 006040 [web], CRI 006041 [web], FLOR, P); Mondaí, 28 August 1964, R. M. Klein 5622 (CRI 006039 [web], FLOR); Nova Teutônia, 27 September 1943, P. Plaumann 133 (RB); São Joaquim, próximo da ponte do rio invernadinha na estrada que liga São Joaquim a São José dos Ausentes, 28 ° 26 ’ 26.44 ’’ S, 49 ° 53 ’ 18.55 ’’ W, 4 November 2016, A. Nuernberg et al. 1850 (FLOR); São Miguel d’Oeste, Canela Gaúcha, 01 September 1964, R. M. Klein 5744 (CRI 006043 [web], FLOR, P); Urubici, 27 ° 59 ’ S, 49 ° 38 ’ W, 4 November 2016, A. Nuernberg et al. 1857 (FLOR). PARAGUAY. Alto Paraná: Tatiyupi, sitios bajos e humedos, 8 July 1987, R. Degen 241 (CTES); Itapúa. Bella vista, 7 October 1993, A. Krapovickas & C. L. Cristóbal 44489 (CTES). URUGUAY. Florida: Timote, Santa Clara, 10 October 1943, R. Gallinal et al. PE 5309 (MO 04782008 [web]); Montevideo: Montevideo, F. Sellow s. n. (M- 0172320 [web]).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7CFF83FF7FFC437B8EFC93.taxon	description	Stoloniferous herb. Stem slender, up to ca. 60 cm tall, reddish; shorter hairs ca. 0.1 mm long, patent, sometimes curved, thin, moderate to very abundant; longer hairs 0.5 – 1 (1.5) mm long, ascending, patent and descending, sparse to moderate, abundant in young parts; glandular hairs ca. 0.5 mm long, sparse to moderate; internodes 0.2 – 8.8 cm long, alternating between very short internodes and long internodes, nodes radicant. Stipules 1 – 4.5 × 1.5 – 3 mm, semicircular, connate to the petiole, hairs 1 – 1.5 mm long, sparse to moderate; petioles 3 – 26 cm long; shorter hairs 0.1 – 0.2 mm long, curved, occasional to moderate (abundant in specimens from grasslands); longer hairs 1 – 2 mm long, ascending, patent and descending, moderate to very abundant, especially in the young parts; glandular hairs ca. 0.5 mm long, occasional to moderate; pulvina ca. 1 mm long, hairs 1 – 2 mm long, patent, abundant. Leaf blades 1.1 – 3.7 × 0.6 – 2.9 cm, coriaceous, widely obovate to obovate, discolorous, the base cuneate, the apex obtuse to rounded, eventually retuse, sometimes acute in young leaves; shorter hairs ca. 0.3 mm long, appressed, occasional to sparse; longer hairs 1 – 1.5 mm long, appressed and ascending, occasional to moderate along veins, moderate to abundant throughout; glandular hairs ca. 0.5 mm, absent or sparse adaxially; longer hairs 1 – 2 mm long, appressed, very abundant throughout abaxially. Dichasia with up to 5 flowers, shorter than the leaves; peduncle 0.5 – 3.2 cm long, shorter hairs 0.1 – 0.2 mm long, curved or appressed, ascending and descending, abundant; longer hairs 0.5 – 1 mm long, patent, ascending or descending, moderate to abundant; glandular hairs ca. 0.5 mm long, sparse to moderate; bracts 1 – 1.5 × 0.5 mm, lanceolate; bracteoles 0.5 – 1 × 0.5 mm, lanceolate. Pedicels 2 – 11 mm long; sepals 2.6 – 4 × 0.75 – 1.5 mm, base rounded, apex acute, shorter hairs ca. 0.3 mm long, moderate, longer hairs 0.5 – 1 mm long, appressed to ascending, moderate to abundant, sometimes concentrate in the margin, glandular hairs ca. 0.5 mm, sparse; petals yellow, 9 – 12 mm long, spatulate, the apex crenate-denticulate, adaxially with glandular hairs, moderate; shorter stamens ca. 3 mm long, glabrous, longer hairs ca. 5 mm long, with hairs ascending; pistil ca. 6 mm long, hairs ascending, abundant, stigmas papillose. Capsules 2.4 (4.1) – 4 (6.3) × 2.1 mm, depressed ovoid, 5 - lobed, hairs ca. 0.5 mm long, ascending, moderate. Seeds 1 per locule, ca. 3 × 2.2 mm, widely elliptic to elliptic, the base rounded, the apex acute.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7CFF83FF7FFC437B8EFC93.taxon	distribution	Distribution and habitat: — This species is endemic to Rio Grande do Sul state, where it is commonly found along the central-northern coast in butiazais, a vegetation type on sandy soils with Butia spp. (Arecaceae), but also at nearby localities (e. g., Depressão Central, Serra do Sudeste), and with a disjunct record at Santiago, in the western part of the state, which is characterized by grasslands on shallow sandy soils. Phenology: — Flowers and fruits have been collected from August to February.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7CFF83FF7FFC437B8EFC93.taxon	etymology	Etymology: The name of this species refers to the Pampa biome, where the species occurs (IBGE 2019). Conservation status: — Oxalis pampeana was collected at seven different localities, but it has never been recorded at any protected area, and the places where it is found are mostly degraded due to urban expansion at coastal areas and agricultural activities. Its AOO is 28 km ², with an infered decline in the area extent and habitat quality, so we recommend its classification as endangered [EN B 2 a, b (iii)].	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7CFF83FF7FFC437B8EFC93.taxon	materials_examined	Nomenclatural notes: — There are four sheetes of “ N. I. Matzenbacher 230 ” at P, and according to the Art. 9.17 of ICN, a second-step lectotypification may be necessary. We selected P 02440126 as the second-step lectotype because it fits unambiguously the description of the protologue, and bears more leaves and more clearly visible inflorescences compared to the isolectotypes.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7CFF83FF7FFC437B8EFC93.taxon	discussion	Taxonomic comments: — Oxalis pampeana is similar to O. bifrons, from which it can be distinguished by widely obovate to obovate (vs. widely depressed obovate to very widely obovate leaflets), with the abaxial blade surface entirely covered by hard appressed and very abundant hairs 1 – 2 mm long (vs. with curved, ascending or patent abundant hairs 0.1 – 0.2 mm long, and appressed, moderate to abundant longer hairs 1 – 2 mm long not entirely covering the blade abaxial surface). Moreover, the inflorescences of Oxalis pampeana are up to 5 - flowered (vs. up to 13 - flowered in O. bifrons), and their geographic distributions do not overlap (figs. 6, 12).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7CFF83FF7FFC437B8EFC93.taxon	materials_examined	Specimens examined: — BRAZIL. Rio Grande do Sul: Arroio dos Ratos, Granja Faxinal, 23 August 1975, K. Hagelund 9216 (P); K. Hagelund 9220 (P); Fazenda Faxinal, 14 October 1979, K. Hagelund 13099 (ICN); 29 August 1981, D. B. Falkenberg 236 (FLOR); 24 August 1985, F. A. Silva-Filho 478 (FLOR); Cidreira, Fazenda Azaléia, próximo à Lagoa Manuel Nunes, 19 July 2012, E. Valduga 478 (HUCS [photo]); Encruzilhada do Sul, 13 Km N do Rio Camaquã no Passo dos Marinheiros, B. Irgang et al. s. n. (ICN 20633); Osório, Fazenda do Arroio para Osório, September 1957, B. Rambo 61463 (P); Palmares do Sul, 1 October 2010, I. Boldrini 1688 (ICN); Santiago, de Santiago para Florida, 2 October 2011, A. A. Schneider 1751 (ICN); Torres, 25 September 1969, J. Favalli et al. s. n. (ICN 7043); Butiazal atrás do posto Esso, próximo da BR 101 e do posto da Polícia Rodoviária Federal, 27 October 1981, D. B. Falkenberg 205 (FLOR); butiazal, 4 February 1984, K. Hagelund s. n. (ICN 106819); 29 ° 21 ’ 12.5 ’’ S, 49 ° 47 ’ 23.3 ’’ W, 6 November 2016, A. Nuernberg et al. 1875 (FLOR).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7EFF8DFF7FFC2F7B06FEF6.taxon	description	Scandent caespitose subshrub. Stem slender, up to ca. 180 cm tall; shorter hairs ca. 0.1 mm long, curved, ascending and patent, very abundant; longer hairs ca. 1 mm long, ascending and patent, abundant; glandular hairs ca. 1 mm long, occasional to moderate; internodes 0.2 – 3.5 cm long. Stipules 1.5 – 3 × 1.2 mm, semicircular, the apex connate to the petiole, petioles 1.7 – 3.8 cm long; hairs as in stem; pulvina ca. 0.1 mm long. Leaf blades 9.5 – 15.1 × 10 – 13.5 mm, coriaceous, widely depressed obovate to very widely obovate, discolorous, the base cuneate, the margin revolute, the apex retuse to rounded, sometimes mucronulate; shorter hairs ca. 0.1 mm long, ascending and curved, occasional to abundant adaxially, very abundant abaxially; longer hairs 1 – 2 mm long, ascending and patent, sparse adaxially, very abundant abaxially; glandular hairs ca. 1 mm long, occasional adaxially, occasional to sparse abaxially. Dichasia with 3 flowers, longer than the leaves; peduncle 5.6 – 8 cm long, hairs as in stem; glandular hairs moderate; bracts 2.6 – 4 × 0.5 mm, lanceolate; bracteoles 2 × 0.5 mm, lanceolate. Pedicels 5 – 11 mm long; sepals 6.5 – 10 × 2.5 – 3 mm, base rounded, apex acute; hairs up to ca. 1 mm long, simple and glandular, appressed and ascending, abundant; petals yellow, 13.8 – 18.7 mm long, spatulate, the apex crenate-denticulate, adaxially with abundant glandular hairs; shorter stamens ca. 4 mm long, glabrous, longer ca. 6 mm long, with ascending hairs; mid-styled pistil ca. 5 mm long, hairs ascending, abundant, stigmas papillose. Capsules ca. 4 × 4 mm, very widely ovoid, 5 - lobed, hairs ca. 2 mm long, patent, abundant. Seeds 1 per locule, ca. 2 × 1.5 mm (immature), widely elliptic to elliptic, the base rounded, the apex acute.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E7EFF8DFF7FFC2F7B06FEF6.taxon	distribution	Distribution and habitat: — This species is endemic to the surroundings of Curitiba (Paraná state), where it was found in the municipalities of São José dos Pinhais and Piraquara, always associated to swamps along the Rio Pequeno lake. Phenology: — Flowers and fruits have been collected from September to March. Conservation status: — Oxalis paranaensis is restrict to swamps along a small river running to Iguaçu river. Even if the population is flourishing, it is very near to Pinus plantation. Indeed, any lake alteration could impact drastically the entire population. In general, Oxalis paranaensis habitat is threatened by silviculture expansion, urbanization, water regime alteration and polution. The species is currently listed as Critically Endangered (CR) (MMA 2014). Nomenclatural notes: — In the original publication, Lourteig (2000) indicated two specimens deposited at P as the “ holotype ” and “ isotype ” of Oxalis paranaensis. However, she did not distinguish among these two exsiccatae which one was the “ holotype ”. Based on Art. 9.17 of the ICN, we selected P 02440281 as the second-step lectotype because it bears more material, with dissected flowers and fruits, and fits unambiguously the diagnostic morphological traits indicated in the protologue. Other duplicates from CTES, FUEL, MO, UM, SPF, and S are listed as isolectotypes. Taxonomic notes: — This species can be easily recognized among the other species of Oxalis sect. Ripariae by the small leaflet blades (9.5 – 15.1 × 10 – 13.5 mm), very widely obovate to widely depressed obovate, base cuneate, apex retuse to rounded, sometimes mucronulate, discolorous, with the abaxial surface densely covered with whitish hairs. It is morphologically similar to Oxalis benjaminii, from which it differs by the cespitose habit with branches ca. 1 m long, leaning on other plants (vs. decumbent stem, branching from the base in O. benjaminii), and 3 - flowered (vs. 5 - flowered) inflorescences. Specimens examined: — BRAZIL. Paraná: São José dos Pinhais, Rio Pequeno, 11 January 2018, A. Nuernberg et al. 1951 (FLOR); 17 January 1969 G. Hatschbach & J. Fontella 20785 (FURB 02905 [web], HCF 000004685 [web], MBM, P, W 1992 - 0016717 [web]); 18 October 1980, G. Hatschbach 43223 (HUEFS 0005050 [web], MBM); 4 March 1980, G. Hatschbach 42777 (MBM, NY 00470509 [web]); 28 December 1982, R. Kummrow 2145 (MBM); Rodovia BR- 277, próximo ao Rio Pequeno, 15 February 1995, J. M. Silva 1427 (HCF 000004687 [web], MBM, P, SJRP 00009149 [web]); 07 November 1996, O. S. Ribas et al. 1599 (ALCB 036719, SJRP 00009150) [web]; 18 October 1998, O. S. Ribas 2739 (MBM); 29 January 2002, O. S. Ribas et al. 4271 (HUEFS 067685 [web], MBM, SPF 00153353 [web], W 2003 - 0000494 [web]); 27 March 2007, J. M. Silva & E. Barbosa 5647 (FURB 36677 [web], HCF 000004686 [web], MBM); 22 September 2015, P. Fiaschi et al. 4477 (FLOR); Piraquara, Santa Maria, 11 October 1969, G. Hatschbach 22423 (ASU 0033852 [web], MBM, P).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E70FF8FFF7FFE937A3BFDB2.taxon	description	C ² 2080 (P 02440316! image of the lectotype available at https: // plants. jstor. org / stable / viewer / 10.5555 / al. ap. specimen. p 02440317; isolectotypes: F 0066532 F [web]!, P 02440318!, MPU 018619 [web]!). (figs. 12, 15).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E70FF8FFF7FFE937A3BFDB2.taxon	distribution	Distribution and habitat: — This species occurs in grasslands and forest edges in the Pampa domain and neighbor areas, with records from Argentina, Uruguay and Brazil (Rio Grande do Sul) (fig. 15). Phenology: — Flowers and fruits have been collected from August to December. Conservation status: — Oxalis refracta has a wide extent of occurrence (EOO = 623,991 km 2), but its distribution is discontinuous, with usually small populations occupying in total an area of occupancy of about 76 km ². Its habitat suffers an accelerated decline due to soil use conversion to agricultural activities. Oxalis refracta has not been recorded in protected areas, which are few in the Pampa domain, but its habitat still has good connectivity, so we consider that it should be categorized as near threatened (NT). Typification of Oxalis refracta: — In the original description, Saint-Hilaire (1825) proposed a beta-variety (named “ debilis ”) for his Oxalis refracta (see treatment of this name under O. niederleinii). The type material of Oxalis refracta var. refracta (the alfa-variety, see Art. 26.3 of ICN) was collected in “ sylvulis humidis umbrosisque ad ripas rivuli dicti Arroio del Rosario, provincial Cisplatina ”, and lectotypified by Lourteig (1983), who mentioned Saint-Hilaire C ² 2080 at P as the “ holotype ”. We traced two samples of Saint-Hilaire C ² 2080 at P, and according to the Art. 9.17 of ICN, we selected P 02440316 as the second-step lectotype, because it is the most complete specimen and perfectly fits the original description. These specimens (Saint-Hilaire C ² 2080) correspond to a morphological extreme in the continuum of hair density of Oxalis refracta, with a much sparser indumentum than at most specimens examined here. Taxonomic notes: — Oxalis refracta is similar to O. niederleinii, from which it can be distinguished by glandularviscid hairs up to ca. 1.5 mm long, which are abundant to very abundant (rarely sparse) throughout the plant (vs. glandular hairs ca. 0.2 mm long, sparse to moderate in reproductive organs in O. niederleinii), more densely arranged leaves (vs. sparse), smaller leaflet blades (7 – 10 × 5 – 7 mm vs. 4 – 20 × 6 – 20 mm), shorter peduncles (2.5 – 5.5 mm vs. 3,5 – 12,5 cm long), inflorescences with 2 – 3 flowers (vs. up to 13 flowers), and larger capsules [5 – 6 (7 – 10) × 12 – 15 mm vs. 2 – 5 × 3 – 5 mm]. Additional note: — Due to its dense glandular hairs, Oxalis refracta can become very sticky, and there are reports of allergenic contact likely due to these glandular hairs content (Laura S. Fetter, pers. comm.). Specimens examined: — ARGENTINA. Buenos Aires: Tornquist, Co Ventana 400 msm, 20 October 1979, C. A. Naranjo 482 (SI); Tandil, La Cascada, 25 November 1937, N. S. Troncoso 1266 (SI); 12 November 1907, C. M. Hicken 19811 (SI); Entre Ríos: Concepción del Uruguay, Quinta del colegio, 13 September 1875, P. G. Lorentz 272 (S-R- 10012 [web]); Diamante, quebrada del cementerio, 17 December 1960, A. Burkart 22197 (SI); 3 November, A. Burkart 27978 (SI); Punta Gorda, 10 November 1985, N. M. Bacigalupo 1457 (SI); Gualeguaychu, Punta Caballo, Barranca, 13 December 1974, A. Burkart 30895 (SI); Ea. Rincón de Landa, sobre el Río Uruguay, a la altura de Perdices, 30 October 1990, N. M. Bacigalupo 1457 (SI); La Paz, Santa Elena, Barrancas, 23 October 1971, A. Burkart 28696 (SI); A. Burkart 28696 (SI); Hernandarias, Pto. Víbora, 5 December 1986, E. R. Guaglianone et al. 202 (SI); La Pampa: Lihuel Calel, Sierra de L. Calel, co. “ de la Sociedad ”, ladera E, en cañadón, 16 October 1979, D. de Azkue s. n. (SI 111691); Misiones: Apostoles, Cnia las Tunas, 3 October 1995, M. E. Torri 220 (CTES); Escuela Agrotécnica Pascual Gentilini, 21 August 1978, A. L. Cabrera & N. S. Troncoso 29269 (SI); Ruta Prov. 1. Arroyo Tunas, 27 ° 55 ’ S, 55 ° 37 ’ W, 24 September 2000, M. E. Múlgura 2326 (SI); Candelaria, Loreto, camino hacia ruta de Santa Ana Oberá, 27 ° 20 ’ S - 55 ° 32 ’ W, 22 September 2000, M. E. Múlgura 2240 (SI); BRAZIL. Rio Grande do Sul: Giruá, Granja Sodol, 26 September 1965, K. Hagelund 3872 (ICN); s. d., K. Hagelund 1109 (ICN); Santana do Livramento, João Duarte, Cerro do Registro, 11 November 2009, E. Barbosa et al. (RB 615285); Agudo, 10 October 2015, J. P. R. Ferreira 773 (FLOR); São Pedro do Sul, 28 October 2016, A. Nuernberg 1829 (FLOR); URUGUAY. Lavalleja: Minas, Cerro Arequita, 11 October 1970, A. Krapovickas 16153 (CTES); Maldonado: Piriapolis, Cerro del Toro, 34 ° 51 ’ 45 ’’ S, 55 ° 15 ’ 03 ’’ W, 18 October 2010, M. E. Morrone 6328 (SI); Cerro Pan Azucar, 13 October 1970, A. Krapovickas 16319 (CTES); Montevideo: Montevideo, Martínez 560 (SI); Sierra de Solís, C. E. O. Kuntze s. n. (NY- 00370276 [web]).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E72FF89FF7FFDCF7C16F8F4.taxon	description	Stoloniferous herb. Stem slender 0.30 – 1 m long; hairs 0.5 – 1 (2) mm long, appressed, ascending or descending, rarely very occasional, normally moderate to abundant, very abundant in younger parts; internodes (0.5) 1.1 – 12.7 cm long, nodes slightly radicant. Stipules absent, or stipules inconspicuous 3 – 4.5 × 1 – 1.5 mm, elongated, narrow, apex semicircular, glabrous, petiole 2.5 – 9.5 (18) cm long; shorter hairs 0.5 – 1 mm long, ascending, patent and descending, abundant, rarely occasional; longer hairs 1.5 – 2 mm long, patent, very abundant in younger parts, or absent in some specimens; pulvina ca. 1 (1.5) mm long; hairs 0.5 – 1 mm, appressed, ascending or patent, moderate to abundant. Leaf blades 0.8 – 3.6 × 1 – 3.1 (4.1) cm, widely depressed obovate to widely obovate, chartaceous or membranous, slightly discolorous, the base cuneate to obtuse, the apex emarginate to obcordate, occasionally mucronulate, or rarely cleft, hairs ca. 0.5 mm long, appressed, sparse to moderate, rarely occasional adaxially; hairs ca. 0.5 mm long, appressed, sparse to abundant, rarely occasional abaxially. Dichasia with 3 – 7 flowers, longer than the leaves, peduncle 1.7 – 9 (11) cm long, glabrous or shorter hairs ca. 0.2 mm, appressed, ascending or descending, very occasional or most commonly moderate to abundant; longer hairs 0.5 – 1 mm, ascending, patent and descending, moderate to abundant, or rarely hairs ca. 0.2 mm, appressed, occasional, or absent; bracts 2 – 6 × 0,3 – 1 mm, lanceolate, hairs (0.2) 1 mm long, appressed, moderate to abundant, rarely occasional; bracteoles 1,5 – 2 × 0.2 – 0.5 mm, lanceolate. Pedicels 5 – 24 mm long; sepals 4 – 7 × 1 – 2 mm, base rounded, apex acute, hairs (0.2) 1 mm long, ascending, sparse; petals yellow, 9 – 18 mm long, spatulate, the apex crenate-denticulate, adaxially with very occasional glandular hairs; shorter stamens ca. 3 – 5 mm long, glabrous, longer 4.5 – 7 mm long, with hairs ascending; pistil 7 – 10 mm long, hairs ascending, abundant, stigmas papillose. Capsules 5 – 7 × 2 – 3 mm, ovoid, 5 - lobed, hairs ca. 1 mm long, ascending, sparse. Seeds 1 – 3 per locule, ca. 2.1 × 1.1 mm, elliptic, the base rounded, the apex acute.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E72FF89FF7FFDCF7C16F8F4.taxon	distribution	Distribution and habitat: — This species was previously reported from the states of Minas Gerais, São Paulo, and Paraná (Lourteig 1983, 2000), and here the known distribution is expanded to Santa Catarina and Rio Grande do Sul states (fig. 17), due in part to the inclusion of Oxalis irreperta as its nomenclatural synonym (see below). Oxalis riparia usually grows at riverbanks and riparian forest edges.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E72FF89FF7FFDCF7C16F8F4.taxon	biology_ecology	Phenology: — Flowers and fruits have been collected throughout the year.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E72FF89FF7FFDCF7C16F8F4.taxon	conservation	Conservation status: — Oxalis riparia has an extent of occurrence (EOO) of about 133,244 km ², with an area of occupation (AOO) of ca. 60 km ². There are only few recent collections of this species in the last ten years, but it is presumably protected at some protected areas, so we suggest it should be categorized as near threatened (NT).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E72FF89FF7FFDCF7C16F8F4.taxon	discussion	Typification of Oxalis riparia: — According to Lourteig (1983), the “ type ” of O. villosa Progel (“ In Brasilia meridionali: Sello ”, B), i. e., the specimen belonging to the original material, was destroyed in 1943 during World War II. When Norlind (1926) proposed O. riparia as a replacement name for O. villosa Progel, he did not indicate any type. The neotypification later carried out by Lourteig (1983: 46) was not legitimate, due to the existence of the original illustration of flower details by Progel (1877: Tab. CIV, Fig. II). This illustration is therefore selected as the lectotype. However, as it does not allow an unambiguous identification of the taxon, an epitype is also indicated, in accordance with Art. 9.9 of the ICN. Taxonomic notes: — Oxalis irreperta is here treated as a synonym of O. riparia. According to Lourteig (1983) these two species could be distinguished by the inconspicuous stipules in Oxalis irreperta (vs. absent in O. riparia), and a sparser indumentum in O. irreperta when compared with O. riparia. However, the type of Oxalis irreperta does not bear stipules, and only differs by the indumentum density from other samples of O. riparia from the same locality (Cerro Azul, Paraná). Stipules were observed in R. Reitz & R. M. Klein 13588, whose leaves have longer petioles and glabrescent leaves with the apex cleft, while another sample with similar leaves (A. Butzke et al. s. n.) do not bear stipules, suggesting that the features used by Lourteig (1983) to distinguish the two species might not justify their recognition. Oxalis riparia can be distinguished from other species of O. sect. Ripariae by the combination of rhizomatose herbaceous habit and leaflets incised at apex, while the remaining species either lack an incised apex (O. bifrons, O. hepatica, and O. sarmentosa) or have a decumbent shrubby (O. eriocarpa and O. refracta) or stoloniferous herbaceous (O. niederleinii) habit.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E72FF89FF7FFDCF7C16F8F4.taxon	materials_examined	Specimens examined: — BRAZIL. Minas Gerais: Caldas, August 1854, G. A. Lindberg 297 (S-R- 9808 [web]); 12 October 1855, I. Regnell 42 (P); Campinas, próxima a estrada para Carmo de Minas, R. Mello-Silva et al. 82 (SPF 00067645 [web]); Delfim Moreira, 21 April 1939, M. Kuhlmann & Gehrt s. n. (SP, CEN, SPF 00140648) [web]; 18 October 1950, M. Kuhlmann & A. Gehrt (SP 40242 [web]); Lagoa Santa, 28 August 1964, J. E. B. Warming 1020 (NY 00470564 [web]!); Lambari, 1935, P. P. Horta s. n. (RB 00271012 [web]); March 1942, H. Delforge s. n. (RB); Ouro Fino, 11 May 1927, F. C. Hoehne s. n. (SP 19576, SPF 00163085 [web]); Poços de Caldas, 20 January 1980, A. Krapovickas & C. L. Cristóbal 35402 (CTES); Santa Rita do Sapucaí, Serra da Bela Vista, 6 July 1996, O. S. Ribas 1424 (MBM); São Thomé das Letras, Baipendi, 14 July 1950, A. C. Brade & Cepparieio s. n. (RB); Paraná: Adrianópolis, Parque Estadual das Lauráceas, trilha da caverna, 24 ° 51 ’ 12.7 ’’ S, 48 ° 43 ’ 08.6 ’’ W, 14 September 2017, E. D. Lozano 3832 (FLOR, MBM); Cerro Azul, Shaded sandbank of rio Ribeiro at foot of forested steep S-slope, ca. 10 km W of Cerro Azul, 14 August 1966, J. C. Lindeman 2314 (P); Estrela, 22 July 1970, G. Hatschbach 24514 (MBM, MO 1061595 [web], NY 00470563 [web], P, SP); G. Hatschbach 24519 (SP); barra do Lageado Grande, 31 August 1978, G. Hatschbach 41571 (MBM, MO 1061593 [web], P, SP); Rio Grande do Sul: Erechim, estrada de Aratiba, 20 October 1995, A. Butzke et al. s. n. (NY 3321126 [web]); Santa Catarina: Santa Catarina: Canoinhas, 26 October 1962, R. Reitz & R. M. Klein 13588 (CRI 006026 [web]!, FLOR, P); Itajaí, rio do Testo (Pomerode), 12 February 1905, F. Muller 417 (K 001198510 [web]!); São Paulo: Águas de Prata, Reserva Estadual de Águas de Prata, 21 ° 52 ’ S, 47 ° 20 ’ W, 21 March 1994, A. B. Martins 31415 (SP, SPF 00098475 [web]!); Amparo, Monte Alegre, estação experimental, April 1943, M. Kuhlmann 472 (SP, SPF 00140649 [web]!); Joanópolis, Estrada para Campos de Jordão, 13 October 1979, P. G. Windisch 2518 (P); São Paulo, Serra da Bocaina, caminho de Alambari, 1 January 1932, B. Lutz 736 (P).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E74FF8AFF7FF88C783BFE0B.taxon	description	Stoloniferous herb. Stem slender ca. 60 cm long, reddish or not, shorter hairs ca. 0.1 mm long, patent, absent or occasional to moderate, longer 0.5 – 1.5 mm long, ascending, patent and descending, occasional to abundant, glandular hair 0.5 mm, sparse; internodes 0.1 – 10.5 cm long, alternating between short and long, radicant nodes. Stipules 2.5 – 4 × 1.5 – 2 mm long, semicircular or rectangular, connate to the petiole, margin with hairs 1 – 2 mm long, patent, moderate to abundant, rarely sparse; petiole 3 – 30.5 cm long; shorter hairs ca. 0.1 long, curved or patent, occasional to moderate; longer hairs 1 – 1.5 mm long, ascending, patent and descending, sparse to moderate; glandular hairs ca. 0.5 mm, absent or sparse to abundant; pulvina ca. 1 mm long, hairs ca. 1 mm long, patent, moderate to abundant. Leaf blades 0.9 – 7.6 × 0.7 – 4.6 cm, coriaceous, widely rhombic to rhombic, discolorous, abaxially purplish or light green, the base cuneate, the apex acute, rarely obtuse or rounded, lateral leaflets asymmetrical with respect to the central vein, adaxially glabrous or with hairs (0.1) 0.5 – 2 mm long, appressed, moderate; glandular hairs 0.5 mm, moderate; abaxially glabrous or with shorter hairs 0.2 – 0.5 mm long, appressed or ascending, occasional; longer hairs ca. 1 (2) mm long, appressed or ascending, occasional to moderate; glandular hairs, if present, 0.5 – 1.5 mm long, sparse to moderate, margin with hairs ca. 1 mm long, ascending, abundant. Dichasia with up to 12 flowers, shorter than the leaves; peduncle 4.4 – 18 cm long; shorter hairs ca. 0.1 mm long, patent or curved, moderate; longer hairs 0.5 – 1.5 mm long, ascending and descending, moderate; glandular hairs ca. 1 mm, moderate; bracts 1 – 2 × 0.5 – 1 mm, lanceolate; bracteoles 1 × 0.3 mm, lanceolate. Pedicels 1 – 12 mm long, sepals 2.5 – 3 × 0.75 – 1.5 mm, green with apex reddish, base rounded, apex acute; shorter hairs ca. 0.1 mm long, occasional, ascending; longer hairs ca. 1 mm long, ascending or patent, sparse; glandular hairs ca. 1 mm long, moderate; petals yellow, 7 – 11 mm long, spatulate, the apex crenate-denticulate, adaxially with moderate glandular hairs; shorter stamens ca. 3 mm long, glabrous, longer ca. 5 mm long, with hairs ascending; pistil ca. 5 mm long, hairs ascending, abundant, stigmas papillose. Capsules ca. 3 × 3 mm, very widely ovoid, 5 - lobed, hairs ca. 1 mm long, ascending, abundant. Seeds 1 per locule, ca. 2.8 × 1.9 mm, widely elliptic to elliptic, base rounded, apex acute, surface crested.	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
557C03465E74FF8AFF7FF88C783BFE0B.taxon	distribution	Distribution and habitat: — This species is found in the southern Brazilian states (Paraná, Santa Catarina, and Rio Grande do Sul) (fig. 16), always associated to Araucaria forests and nearby grasslands. Phenology: — Flowers and fruits have been collected from March to July. Conservation status: — Despite the restricted distribution, this species is frequent within its range, and it has been recorded in several protected areas. For these reasons we suggest it should be considered as low concern (LC) regarding extinction risk. Nomenclatural notes: — Zuccarini (1832) reported in the protologue that he examined a dried specimen by Sellow from southern Brazil. As no further detail is provided, this specimen represents a syntype (Art. 9.6 of ICN). Lourteig (1983: 39) reported: “ the holotype with Zuccarini’s handwritting is from his personal herbarium and does not indicate the collector number, which is usual for his herbarium. Sellow’s number (3942) appears only at LISU herbarium ”. Lourteig (1983) carried out a lectotypification when citing the “ holotype ” at M (see also Prado et al. 2015), but this choice requires a second-step lectotype to distinguish between M- 0172385 and M- 0172386 (see Art. 9.17 of ICN). M- 0172385 is here chosen since it is the most complete specimen, and perfectly fits the original description. Taxonomic notes: — This is the most common stoloniferous species of Oxalis sect. Ripariae from southern Brazil. Sometimes it can be confused with Oxalis bifrons, whose leaflets are wider above de mid portion and the apex is rounded, while in O. sarmentosa the leaflets are wider at or below the mid portion, with a usually rounded apex. Moreover, leaf abaxial surface in Oxalis sarmentosa is glabrous or with straight short hairs 0.2 – 0.5 mm long and larger hairs ca. 1 (– 2) mm long, with a predominance of the larger ones over the shorter ones, while in O. bifrons the abaxial surface has shorter curved hairs 0.1 – 0.2 mm long and longer hairs 1 – 2 mm long, with the shorter ones predominating over the longer ones. Specimens examined: — BRAZIL. Paraná: Lapa, Passa Dois, orla de capão, 30 October 1969, G. Hatschbach, 22744 (MBM, P, W 199302868 [web]); em rodovia 476 que liga Lapa a São Mateus do Sul, próximo km 201, 25 ° 46 ’ 25.9 ’’ S, 49 ° 45 ’ 32 ’’ W, 1 January 2016, A. Nuernberg et al. 1813 (FLOR); Ponta Grossa, Itaiacoca, 4 October 2007, J. M. Silva et al. 6100 (ALCB 036740 [web], FUEL, FURB 02907 [web], HCF 000004705 [web], HUEFS 0146698 [web], HUFU 00019422 [web], MBM, SPF 00190566 [web]); Parque Nacional dos Campos Gerais, 25 ° 07 ’ 33.7 ’’ S, 49 ° 56 ’ 31.19 ’’ W, 5 November 2017, A. Nuernberg et al. 1938 (FLOR); Rio Grande do Sul: Cambará do Sul, 21 September 1979, K. Hagelund 13094 (ICN); Ponte sobre rio Camisas RS 020, 31 August 2002, V. F. Kinupp 2449 (ICN); RS 020, 29 ° 05 ’ 01 ” S, 50 ° 10 ’ 4.9 ”, 4 November 2016, A. Nuernberg et al. 1862 (FLOR); Parque Nacional Serra Geral, 29 ° 08 ’ 4.64 ” S, 50 ° 03 ’ 2.47 ” W, 6 November 2016, A. Nuernberg et al. 1870 (FLOR); Caxias do Sul, Vila Oliva, 15 July 1954, B. Rambo s. n. (PACA 55868 [web]); Esmeralda, Fazenda da Guabiroba, 3 September 1987, M. Rossato et al. 3249 (MO 3523882 [web], MO 1061612 [web], HUCS [photo]); Farroupilha, 26 September 1957, O. R. Camargo 807 (P); 5 September 1957, O. R. Camargo 1685 (P); Jaquirana, barranco em beira de estrada que vai de Jaquirana a São José dos Ausentes, 28 ° 54 ’ 14.37 ’’ S, 50 ° 20 ’ 28.74 ’’ W, 4 November 2016, A. Nuernberg et al. 1849 (FLOR); São Francisco de Assis, 29 ° 37 ’ 26.4 ’’ S, 55 ° 09 ’ 19.5 ’’ W, 31 October 2016, A. Nuernberg et al. 1838 (FLOR); São Francisco de Paula, Lajeado Grande - RS 476, 12 September 1999, R. Wasum 119 (HUCS [web]); 6 November 2016, P. Webber 554 (FLOR); São José dos Ausentes, Várzea, 27 September 2014, E. Barboza et al. 4216 (MBM); Santa Catarina: Bom Jardim da Serra, Fazenda Santa Rita, 28 ° 17 ’ 54 ’’ S, 49 ° 44 ’ 07 ’’ W, alt. 1407 m, 07 November 2013, A. C. Cervi et al. 10177 (MBM); Campo Alegre, borda de campo, 26 ° 16 ’ S, 49 ° 01 ” W, 2 October 2016, A. Nuernberg et al. 1816 (FLOR); Orleans, Parque Nacional de São Joaquim, Estrada para o Morro da Igreja. Trilha para a Pedra Furada, 28 ° 07 ’ 45 ’’ S, 49 ° 28 ’ 18 ’’ W, 31 October 2014, P. Fiaschi et al. 4391 (FLOR); São Bento do Sul, Minas de Caulin, 4 October 2015, P. Schwirkowski 1223 (FURB); São Joaquim, Fazenda Domingos Borges, 28 ° 26 ’ 24 ’’ S, 49 ° 59 ’ 55,79 ’’ W, 20 September 2014, E. Barboza et al. 4177 (MBM); Fundão do Boava, 28 ° 27 ’ 35.1 ’’ S, 49 ° 53 ’ 26.2 ’’ W, 22 September 2014, E. Barboza et al. 4187 (FLOR, ICN, MBM); beira de estrada que vai de São Joaquim a São José dos Ausentes, 28 ° 26 ’ 26.44 ’’ S, 49 ° 53 ’ 18.55 ’’ W, 4 November 2016, A. Nuernberg et al. 1855 (FLOR); Urubici, Parque Nacional de São Joaquim, Trilha da Cascatinha, 1348 m alt., 28 ° 8 ’ 23.5 ’’ S, 49 ° 37 ’ 49.3 ’’ W, 27 March 2011, P. Fiaschi et al. 3633 (SPF 202781 [web]); estrada para os campos de Santa Bárbara, ca. 2,5 km a partir do alojamento de pesquisadores, campos de altitude 1584 m alt., 28 ° 09 ’ 12.1 ’’ S, 49 ° 38 ’ 10.1 ’’ W, P. Fiaschi et al. 3638 (SPF 202769 [web]); Arredores do alojamento do ICMBio, 21 September 2014, P. Fiaschi et al. 4360 (FLOR); Trilha do alojamento do ICMBio para a Cachoeira, 21 September 2014, P. Fiaschi et al. 4361 (FLOR); PPBio-MA, próximo a TS 4500, 28 ° 09 ’ 55 ’’ S, 49 ° 38 ’ 44 ’’ W, 13 September 2014, A. Nuernberg et al. 1906 (FLOR); Zortéa, Margens PCH Agudo, 13 October 2010, E. Richetti 2 (FLOR).	en	Nuernberg-Silva, Anelise, Fiaschi, Pedro (2021): Taxonomic revision and morphological delimitation of Oxalis sect. Ripariae (Oxalidaceae). Phytotaxa 529 (1): 125-159, DOI: 10.11646/phytotaxa.529.1.11
