Isoetaceae - Quillwort family

Photo: P. Ballings
Zimbabwe

 

Description of the family

Small, submerged or emergent aquatic plants, evergreen or decidiuous, occurring in aquatic or seasonally wet habitats. Rhizome short, corm-like; rootlets dichotomously branched, arising from a basipetal growing point beneath the rhizome. Leaves in a rosette, flat or cylindrical, grass-like, leaf base spathulate with a membranous margin and a delicate triangular ligule on upper surface where leaf narrows. Sporangia sessile, ovoid or globose, initially embedded in the adaxial surface of the leaf base below the ligule, partially or entirely covered by a thin membranous outgrowth (velum), heterosporous.

Worldwide: 1 genus and ± 150 species, cosmopolitan apart from the Pacific Islands.

 

Genera

  • Isoetes L.
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    Literature

  • Crouch, N.R., Klopper, R.R., Burrows, J.E. & Burrows, S.M. (2011) Ferns of Southern Africa, A comprehensive guide. Struik Nature.
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria.
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13: 1-222.
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0: 1-254.
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