Isoetes welwitschii A. Braun

Fischer, Eberhard & Lobin, Wolfram, 2022, The genus Isoetes (Isoetaceae) in Central Africa (Democratic Republic of the Congo, Rwanda, Burundi) with the description of three new species, Willdenowia 52 (3), pp. 315-334 : 330

Isoetes welwitschii A. Braun in Kuhn, Filic. Afr.: 196. 1868. – Holotype: Angola, “Habit.[at] socialis cum Xyridis, Ophioglosso et Cyperaceis in pascuis editis subspongiosis in planitie de Empalanca territoriiis Huillensis”, Apr 1860, Welwitsch 166 ( B 20 0108478; isotype: K000351303 ).

Description — Megaspores c. 400 × 400–440 µm; proximal face trilete, with scattered and large and distant pustules 20–30 µm high and 30–40 µm in diam., and small tubercles 10–20 µm in diam. in between and toward ridges, with sparse threads, ridges free of waxes; distal face with large pustules up to 40 µm high and 30–40 µm in diam., partly anastomosing, and with small tubercles 16–20 µm in diam. toward margin, with sparse threads. – Fig. 7.

Note — Welwitsch wrote on the Kew specimen in ink: “Obs Omnia specimina a me visa habitu et statura pusilla inter se perfecte aequalia!”

Taxonomic treatment