Isoetes - Isoetaceae

Isoetes toximontana L.J. Musselman & J.P. Roux






Common name


Pseudo-corm 3-lobed, roots unbranched; bud scales present. Leaves 3-10, erect, linear to flexuous, needle shaped, elliptic in transverse section, c. 40(-60) x 0.5 mm, flaring to 2.8 mm wide at base. Ligule absent. Velum absent. Sporangia roughly oval to round, c. 3 x 2.8 mm. Megaspores 0.28-0.32 mm in diameter, grey-green turning olive -green when dry, distal surface with occasional rugi and bullae, proximal surface uniformly tuberculate.



toximontana: the type locality is Gifberg in the Western Cape; Gifberg is Afrikaans for poison mountain.


Exposed on seeps with species of Utricularia and Drosera, or otherwise submerged in temporary pools.

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 64 - 65. (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.