Isoetes - Isoetaceae

Isoetes stephanseniae A.V. Duthie

 

 

 

 

Synonyms

Isoetes capensis A.V.Duthie var. stephansiniae (A.V.Duthie) Schelpe & N.C.Anthony

Common name

Description

Pseudo-corm 2-lobed; bud scales triangular, c. 3 x 3 mm, blackish brown, leathery, sometimes with hairlike apical appendage up to 3 mm long. Leaves 5-15, linear, needle shaped, 40-130 x c. 1.5 mm, flaring to 4 mm wide around the sporangia, with narrowly winged membranous margin basally. Ligule cordate-triangular, up to 1 mm long, pale but darkened at the point of attachment. Velum complete. Sporangia almost round, 2-5 mm in diameter. Megaspores 0.45-0.62 mm in diameter, grey-white, distal surface with large warts coalescing into short ridges, proximal surface with scattered warts.

Notes

Derivation

stephanseniae: this species was first found by Miss A.J. Stephansen of Stellenbosch University in 1927.

Habitat

Granitic rock pools and marshy ground in grassland.

Distribution worldwide

See African distribution.

Distribution in Africa

South Africa.

Growth form

Terrestrial.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 30 - 32.
  • Crouch, N.R., Klopper, R.R., Burrows, J.E. & Burrows, S.M. (2011) Ferns of Southern Africa, A comprehensive guide. Struik Nature. Pages 52 - 53. (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.

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