| Home | > | List of families | > | Isoetaceae | > | Isoetes | > | welwitschii |
| Synonyms: |
Calamaria natalensis (Baker) Kuntze Calamaria welwitschii (A. Braun) Kuntze Isoetes natalensis Baker |
| Common names: | |
| Frequency: | |
| Status: | Native |
| Description: |
Small herb 5–20 cm tall. Pseudo-corm 3-lobed, scarcely developed or up to 1.5 cm wide; bud scales dark brown to black, triangular with the tip abruptly narrowed to a sharp point, up to 3 × 7 mm. Leaves 5-35, pale green, erect, slender, 50-350 mm × 4 mm at the base, ± semi-circular in cross-section, apex awl-shaped. Dried specimens often rather distinctly bicolored, whitish at base (sporangial part and about 1.5 cm above it) contrasting with dark green upper parts. Ligule narrowly triangular, 2.5 mm long. Velum absent or rarely a rim ± 1 mm wide. Sporangia suborbicular, up to 2.5 (-9)× 2 (-5) mm. Megaspores of two sizes, about 0.45-0.56 mm in diameter, ash grey to white, distal surface tuberculate with smaller warts interspaced, proximal surface trilete with spaced tubercles confined to the centre or if more extensive then central ones the largest or sometimes ± smooth. Microspores minutely tuberculate. |
| Notes: | |
| Derivation of specific name: | welwitschii: named after the Austrian botanist F. Welwitsch (1806-1872) who first collected this species. |
| Habitat: | Marshy or perennially wet seepage area. |
| Worldwide distribution: | Angola, Botswana, Central African Republic, Eritrea, Ethiopia, Ghana, Kenya, Madagascar, Nigeria, South Africa, Sudan, Tanzania, Zambia. |
| Botswana distribution: | |
| Growth form(s): | Terrestrial. |
| Endemic status: | |
| Red data list status: | |
| Insects associated with this species: | |
| Spot characters: | Display spot characters for this species |
| Literature: |
Burrows, J.E. (1990). Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 34 - 36. (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 68 - 69. (Includes a picture). Jacobsen, W.B.G. (1983). The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Page 154. Roux, J.P. (2001). Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report 13 Page 30. Roux, J.P. (2009). Synopsis of the Lycopodiophyta and Pteridophyta of Africa, Madagascar and neighbouring islands Page 11. |
| Home | > | List of families | > | Isoetaceae | > | Isoetes | > | welwitschii |