Isoetes - Isoetaceae

Isoetes eludens J.P. Roux






Common name


Pseudo-corm 3-lobed, roots long and unbranched; bud scales absent. Leaves 9-14, erect, subulate, gradually tapering to apex, broadly ovate in transverse section, 50 x 3 mm, to c. 10 mm wide around the base, pale green, longitudinally striate. Ligule absent. Velum complete. Sporangia oblong-ovate, to 3.5 x 3 mm enclosed by additional sporangium sac. Megaspores 0.26-0.28 mm in diameter, chalk-white when immature, graphite-black when mature, distal surface smooth or with very little verrucae, proximal surface smooth.



eludens: avoid, evade, frustrate; this species for long eluded its discovery.


Shallow sediment of a small gneiss rock pool at 1300 m at the Kamiesberg in the Nothern Cape.

Distribution worldwide

See African distribution.

Distribution in Africa

South Africa.

Growth form



  • Crouch, N.R., Klopper, R.R., Burrows, J.E. & Burrows, S.M. (2011) Ferns of Southern Africa, A comprehensive guide. Struik Nature. Pages 54 - 55. (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 9.