Cyathea - Cyatheaceae

Cyathea thomsonii Baker

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: BT. Wursten
Zimbabwe

Photo: BT. Wursten
Zimbabwe

 

 

 

 

Synonyms

Cyathea zambesiaca Baker
Alsophila thomsonii (Baker) R. M. Tryon

Common name

Thomson's tree fern

Description

Caudex slender, 2.5 × 0.15 m, without spines and without aphlebia in the crown. Fronds thinly coriaceous, to 2 x 0.8 m. Stipe glossy brown, to 30 cm long, set with dark brown scales towards the base; scales up to 20 mm long, lanceolate, margins pale, lacerate. Lamina up to 2 m long, 2-pinnate to 3-pinnatifid, elliptic in outline, a few of the lower pinnae gradually reduced and more widely spaced. Pinnae narrowly oblong-attenuate, deeply to shallowly pinnatifid, to 40 cm long. Pinnule to 6 x 1 cm, lobes from almost semicircular to oblong, slightly falcate, apex rounded to acute, undersurface with sparce stiff twisted hairs along the costules; rhachis pale brown with twisted hairs when young, becoming hairless at maturity. Sori round, set in 2 rows along each side of the costules; indusium cup-shaped fragmenting with maturity.

Notes

Differs from C. dregei in having a narrower and shorter stem, a 2-pinnate to 3-pinnatifid frond (never 3-pinnate) and shorter stipe scales

Derivation

thomsonii: first collected by J. Thomson (1858-1895), a British plant collector

Habitat

Along shaded streambanks in evergreen or semi-deciduous forest .

Distribution worldwide

See African distribution.

Distribution in Africa

Angola, Burundi, Democratic Republic of Congo, Malawi, Mozambique, Tanzania , Zambia, Zimbabwe.

Growth form

Terrestrial.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Page 86. (Includes a picture).
  • Edwards, Peter J. (2005) Cyatheaceae. Flora of Tropical East Africa, Page 12. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 199 - 200. As Alsophila thomsonii (Baker) R.M.Tryon (Includes a picture).
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Page 88.
  • 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 67. As Alsophila thomsonii (Baker) R.M.Tryon
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Page 72. (Includes a picture).
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