Isoetes - Isoetaceae

Isoetes capensis A.V. Duthie

Photo: JE. Burrows
South Africa






Common name


Pseudo-corm 3-lobed; bud scales triangular, c. 3 x 3 mm, blackish brown, leathery, sometimes with a hair-like apical tip up to 3 mm long. Leaves 5-35, linear in outline, needle-shaped, 30-190 x 1.5-2.5 mm, to 4 mm wide around the sporangia, with a broad hyaline margin at the base. Ligule cordate-triangular, up to 1 mm long, pale but darkened at the point of attachment. Velum complete. Sporangia oval to almost round, 2-5 mm in diameter. Megaspores 0.39-0.57 mm in diameter, grey-white, distal surface reticulate with raised ridges often not linked to the equatorial flange, proximal surface with scattered warts, sometimes coalescing into short ridges.



capensis: from the Cape, this species is endemic to the Western Cape in South Africa.


Seasonally flooded depressions, usually in sandy clay soils.

Distribution worldwide

See African distribution.

Distribution in Africa

South Africa.

Growth form



  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 30 - 32. (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 50 - 51. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 156 - 157. (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 8.