Isoetes schweinfurthii A. Braun ex Baker

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 : 316-330

Isoetes schweinfurthii A. Braun ex Baker in J. Bot. 18: 108. 1880. – Lectotype (designated by Schelpe & Anthony 1986: 28): South Sudan, 2–4' [Fuss] unter

Wasser in einem Regenlauf bei der grossen Seriba Ghattas im Djurgebiet, 20 Jun 1869, Schweinfurth 1962 ( B 20 0108240; isolectotypes: B 20 0108246, B 20 0108247, K000351298 ) .

Description — Megaspores (360–)440–520 × (360–) 440–520 µm; proximal face trilete, laevigate or with up to 3 flat tubercles c. 22.5 µm high and up to 15 µm in diam. per areole, covered with dense threads, ridges c. 60 µm wide and 20–30 µm high, free of waxes; distal face with dense to distant pustules 20–40 µm in diam., partly smaller, anastomosing, larger pustules 80–100 µm in diam., all covered with dense threads. – Fig. 4–6.

Additional specimens studied — BENIN: ATAKORA: Matéti , SE of Dassari, along RNIE (Route Nationale) 3, 10°48.3'N, 01°09.3'E, dried up rice fields, 22 Nov 1999, Van der Maesen, Akoegniaou, Yédomonhau & Agbani 7203 ( BR0000015469366 ) . — TANZANIA ( T4 ): TABORA: 21 km on Tabora–Urambo road, 05°05'S, 32°39'E, 1025 m, 11 Jun 2008, Bidgood, Leloyo & Vollesen 7304 ( K001291892 ) .