New and poorly known " araphid " diatom species (Bacillariophyta) from regions near Lake Titicaca, South America and a discussion on the continued use of morphological characters in " araphid " diatom taxonomy Author Morales, Eduardo A. https://orcid.org/0000-0001-5998-4831 Water Laboratory, University of Evora, P. I. T. E. Rua da Barba Rala No. 1, 7005 - 345 Evora, Portugal & Institute of Earth Sciences - ICT, University of Evora, Rua Romao Ramalho n °. 59, 7000 - 671 Evora, Portugal edu_mora123@outlook.com Author Wetzel, Carlos E. https://orcid.org/0000-0001-5330-0494 Observatory for Climate, Environment and Biodiversity (OCEB), Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, 4422 Belvaux, Luxembourg Author Ector, Luc Observatory for Climate, Environment and Biodiversity (OCEB), Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 41 rue du Brill, 4422 Belvaux, Luxembourg text PhytoKeys 2021 2021-12-13 187 23 70 http://dx.doi.org/10.3897/phytokeys.187.73338 journal article http://dx.doi.org/10.3897/phytokeys.187.73338 1314-2003-187-23 6AF5EAA0500558E5838FD916171188B8

Table 3. Comparison of P. vulpina stat. nov. with most similar triradiate species in Pseudostaurosira and Pseudostaurosiropsis that have LM and SEM information available. ND=not determined. Features in bold italic font are defining for each taxon.

Feature/species	P. iztaccihuatlii V.H. Salinas & D. Mora	P. vulpina stat. nov.	Pseudostaurosiropsis triradiatum (E. Morales) Kulikovskiy, Glushchenko & B. Karthick
Valve dimensions (µm)	L: 6.2-10.8 W: ND	L: 4.8-13.0 W: 4.1-5.6	L: 7-10 W: ND
Stria density (in 10 µm)	12-18	14-16	14-16
Valve outline; axial area; virgae	Triradiate; irregularly triangular, externally and internally depressed with respect to the virgae; wide	Triradiate; irregularly triangular and externally depressed with respect to the virgae, internally at the same level as the latter; wide	Triradiate; triangular, with concave sides, depressed with respect to the virgae in external and internal view; much wider than striae
Areolae; volae; striae	Roundish to transapically elongate; well-developed and with ring-like depositions distorted in different ways at the valve interior; composed of several areolae, a single one on the valve mantle	Roundish to transapically elongated; well-developed and with inverted cone-like accumulations of different shape at the valve interior; composed of several areolae, a single one on the valve mantle	Circular; absent, with rotae instead; composed of up to 4 areolae 2 on valve face and 2 on the mantle
Spines; stipules; flaps	Large, conical base, spatulate tip, slightly slender than basal vimen; absent; absent	Small, conical, slender than basal vimen, sometimes shapeless and occurring on virgae and vimines; absent; absent	Small, conical, wider that basal vimen; absent; absent
Apical pore fields; mantle abvalvar blisters	Depressed, not known from valve interior view; large and extending to the apical portions but below the apical pore field	Depressed, opening into a non-depressed porous plate at the valve interior; large and extending to the apical portions but below the apical pore field	Not depressed, opening internally into a circular depressed zone; ND
References	Salinas et al. (2020)	Rumrich et al. (2000), this study	Morales (2005)