Isoetes transvaalensis C.Jermy & Schelpe

Rhizomorph trilobed, less than 10 mm in diameter; rhizomorph-scales broadly deltate, becoming trilobed and cuspidate, black-brown, nitid, with scarious margins. Sporophylls c. 30-160 x 1-2 mm (when dry), tapered gradually to an acute apex, base broadly deltate with scarious margins 1 mm broad extending up to 20 mm along lamina; ligule flabellate, broader than long, labium shorter than ligule. Sporangium with complete velum, oblong-ovate, up to 4 x 2.5 mm. Megaspores coal-black when moist, greyish when dry, almost smooth on distal and proximal faces, 390-500 µm. Microspores faintly granular, 28-32 µm.