Platycerium - Polypodiaceae

Platycerium alcicorne Desv.

Photo: BT. Wursten
Zimbabwe

Photo: BT. Wursten
Mozambique

Photo: BT. Wursten
Mozambique

Photo: BT. Wursten
Mozambique

Photo: BT. Wursten
Mozambique

Photo: BT. Wursten
Mozambique

 

 

 

 

Synonyms

Elaphoglossum alcicorne (Desv.) Keyserl.
Platycerium bifurcatum aucct. e.g. Hieron., non (Cav.) C.Chr.
Acrostichum alcicorne P. Willemet
Platycerium vassei Poisson

Common name

Description

Rhizome short, c. 1 cm in diameter, rhizome scales brown, subulate, 3.5-12 x 0.5-1.5 mm. Fronds dimorphous. Sterile fronds 20-35 x 8-25 cm, round to reniform, convex, notched at the base and overlapping, forming at maturity an almost hemispherical mass, thinly set with minute hairs, becoming glabrous with age. Fertile fronds up to 60 cm long, narrowly wedge-shaped, reduced towards the base into a short and thick petiole, 2-4 times dichotomously branched, divided into rounded to bluntly pointed segments up to 30 × 2.5 cm, subglabrous above, densely set with minute stellate hairs below. Soral patches generally several per frond (4-8) on the underside of the lamina near but not at the apices of the ultimate lobes; initially median on the segment, reaching from margin to margin and down to the sinus when mature, never covering the segment apex; covered with white stellate hairs.

Notes

This species has been listed as extinct in Zimbabwe due to habitat loss and overcollecting. However we found a specimen very high in an old Albizia adiantifolia and it seems rather unlikely that the specimen was planted there. Although the tree was growing at the edge of a tea plantation, it was not particularly close to any buildings or gardens. When we asked the guides at Aberfoyle about this species they were confident that they had seen more specimens in the area. It would be very good to find if more specimens of this species might have been able to survive in Zimbabwe but more investigation is needed to confirm or deny this.

Derivation

alcicorne: alces: the generic name of an elk, cornu: horn; translating to the common name 'elkhorn'.

Habitat

Deciduous woodland or dry, semi-deciduous forest, evergreen thickets, on Diospyrus mespiliformis and Ficus as solitary trees in cultivations, exposed or partially shaded.

Distribution worldwide

Africa, Comoro Isl., Madagascar, Mauritius, Réunion, Seychelles.

Distribution in Africa

Kenya, Mozambique, Tanzania , Zimbabwe.

Growth form

Epiphytic.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 188 - 189. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 301 - 302. (Includes a picture).
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Page 96.
  • 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 162.
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Pages 145 - 146.
  • Verdcourt, B. (2001) Polypodiaceae. Flora of Tropical East Africa, Page 4. (Includes a picture).
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