taxonID	type	description	language	source
039587DDBF62FF8EFF2DF8B30790DCA5.taxon	description	Scanning electron microscopy (Figs 58 – 65): — Rapheless valve (SV) (Figs 58 – 62): Valve surface with shallow, rounded to irregularly shaped depressions along the apical axis, mainly concentrated in the central area (Figs 58 – 60). Externally, striae multiseriate, composed of three to five rows of small same-sized round areolae (Figs 58 – 60). Striae continuing shortly onto the valve mantle, without interruption (Figs 58 – 59). Internally, cavum covered by a hood with a narrow aperture towards the mantle (Figs 61, 62). Raphe valve (RV) (Figs 63 – 65): Striae composed of three to five rows of rounded areolae, not extended over the valve mantle (Fig. 63). Virgae broader than striae, except near the apices. Externally, proximal raphe endings straight, terminating in expanded drop – like pores. Distal raphe fissures bent, continuing shortly onto the valve mantle (Fig. 63). Internally, striae sunken between raised virgae and composed of areolae covered by individual hymenes (Figs 64, 65). Central nodule raised (Fig. 65). Proximal raphe endings slightly deflected into opposite sides, terminating inconspicuously (Figs 64, 65). Distal raphe endings terminating on poorly developed helictoglossae, continuing shortly onto the valve mantle (Fig. 64).	en	Lai, Giuseppina G., Ector, Luc, Padedda, Bachisio M., Wetzel, Carlos E. (2021): Planothidium marganaiensis sp. nov. (Bacillariophyta), a new cavum-bearing species from a karst spring in south-western Sardinia (Italy). Phytotaxa 489 (2): 140-154, DOI: 10.11646/phytotaxa.489.2.3, URL: http://dx.doi.org/10.11646/phytotaxa.489.2.3
039587DDBF62FF8EFF2DF8B30790DCA5.taxon	materials_examined	Type: — ITALY. Carbonia-Iglesias: San Giovanni cave at Domusnovas (Monte Acqua, Marganai massif), 190 m a. s. l., 39 ° 20 ’ 13.4 ’’ N; 008 ° 37 ’ 37.1 ’’ E, sampling dates 21 September 2016 and 31 January 2017, collected by Giuseppina Grazia Lai (designated here, holotype: slide no. BR- 4636 Meise Botanic Garden, Belgium. Specimen here depicted in Fig. 9).	en	Lai, Giuseppina G., Ector, Luc, Padedda, Bachisio M., Wetzel, Carlos E. (2021): Planothidium marganaiensis sp. nov. (Bacillariophyta), a new cavum-bearing species from a karst spring in south-western Sardinia (Italy). Phytotaxa 489 (2): 140-154, DOI: 10.11646/phytotaxa.489.2.3, URL: http://dx.doi.org/10.11646/phytotaxa.489.2.3
039587DDBF62FF8EFF2DF8B30790DCA5.taxon	etymology	Etymology: — The name refers to the Marganai massif where the karst spring San Giovanni originates. Marganai (Marganái) (Iglesias) — It is an elongated mountain or a mountain of a small mountain chain: it is likely that its name is to be compared — not derived — with Lat. margo, - inis “ margin ” (Indo-European). Cfr. Marghine (Source: Pittau, 2013).	en	Lai, Giuseppina G., Ector, Luc, Padedda, Bachisio M., Wetzel, Carlos E. (2021): Planothidium marganaiensis sp. nov. (Bacillariophyta), a new cavum-bearing species from a karst spring in south-western Sardinia (Italy). Phytotaxa 489 (2): 140-154, DOI: 10.11646/phytotaxa.489.2.3, URL: http://dx.doi.org/10.11646/phytotaxa.489.2.3
