Isoetes - Isoetaceae

Isoetes transvaalensis Jermy & Schelpe






Common name


Pseudo-corm 3-lobed; bud scales few, triangular, acute, c. 2 x 2 mm, dark brown. Leaves 10-30, erect, 30-160 mm long, c. 3 mm at the base, tapering gradually to a slender point. Ligule fan-shaped, the distal margin wavy, wider than the base. Velum complete. Sporangium oblong-ovate, up to 4 x 2.5 mm. Megaspores white when immature and dry, black when old and wet, 0.39-0.5 mm in diameter, distal surface variable, almost smooth to fairly densely covered with rounded tubercles with convex sides, proximal surface similar but warts less pronounced.



transvaalensis: from the Transvaal


On sandstone in montane grassland or on mountain peaks submerged in shallow pools that dry out in winter, c. 1600-2600 m.

Distribution worldwide

See African distribution.

Distribution in Africa

Lesotho, South Africa.

Growth form



  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Page 33. (Includes a picture).
  • Crouch, N.R., Klopper, R.R., Burrows, J.E. & Burrows, S.M. (2011) Ferns of Southern Africa, A comprehensive guide. Struik Nature. Pages 60 - 61. (Includes a picture).
  • Roux, J.P. (2009) Synopsis of the Lycopodiophyta and Pteridophyta of Africa, Madagascar and neighbouring islands. Strelitzia 23, South African National Biodiversity Institute, Pretoria. Page 10.