Isoetes stellenbossiensis A.V.Duthie

Corms 3-lobed, harsh to the touch, up to 1-5 cm diam.; sclerised bases of sporophylls and bud-scales persisting, the latter horny and three-toothed; leaves 5-33, 1.5 to 12 cm long, firm in texture, sheathing base 1 cm or less wide, often narrowing somewhat abruptly above the level of the sporangium; lamina 0-5-1 mm wide, rounded on the back, flat or slightly furrowed above, furnished with stomata; three well-developed groups of strengthening fibres present, one at each angle of adaxial face and one at abaxial end of middle partition; air-canals poorly developed, the adaxial disappearing near the leaf apex; ligule small, delicate in texture, elongate-triangular, sometimes cordate at base, in old leaves often imperfect through decay; velum absent; sporangia varying much in size and shape, the older megasporangia often circular in outline, the younger oval or elliptical; microsporangia conspicuously punctate, innermost often angled by pressure; both mega-and microsporangia rounded on the back and with adaxial face flat or slightly concave, and usually bordered by a narrow rim; some of the cells of the sporangial wall conspicuously thickened, often yellowish-brown in colour; megaspores globose, from 450-590 µ in diam., basal face conspicuously reticulate, reticulations often less regular along the equatorial ridge and on the apical faces; colour of adult megaspores greenish-grey, darkening appreciably on moistening; microspores 32-36 µ long, 16-24 µ broad, brown in colour, spinulose.