Oleandra - Oleandraceae

Oleandra distenta Kunze

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Mozambique

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Mozambique

Photo: P. Ballings
Zimbabwe

 

 

 

 

Synonyms

Aspidium articulatum (Juss. ex Poir.) Willd.
Oleandra densifrons Kunze
Oleandra africana Bonap.
Oleandra distenta Kunze var. hirsuta Tardieu
Oleandra distenta Kunze var. villosa Tardieu
Oleandra articulata 'Cav.' var. welwitschii Bak.
Oleandra welwitschii (Baker) Pic.Serm.
Oleandra distenta Kunze var. welwitschii (Baker) Kornas

Common name

Description

Rhizome long creeping, up to 4 mm in diameter, scandent, branched; rhizome scales appressed, shiny, lanceolate, up to 7 mm long, with a dark brown central stripe and paler ciliate margins. Roots thin, wiry, singly below each old frond. Fronds widely spaced on rhizome or on short side branches, erect to arching, deciduous, simple. Stipe articulated near the base, up to 6 cm long, covered with scattered scales similar to, but smaller than those on the rhizome. Lamina 14-33 × 1.5-6.5 cm, glabrous on both surfaces, thinly membranous (dry) to thinly coriaceous, linear lanceolate in outline, base wedge-shaped, apex abruptly ending in a tip, margin subentire, wavy; midrib prominent below; veins obvious, simple, sometimes forked near the costa, finely parallel. Sori circular, up to 2.5 mm in diameter, in a irregular line on either side of the midrib, situated within the inner half of the lamina; indusium round to kidney-shaped, small, hairless, dark brown, entire.

Notes

Can be separated from other ferns by the rampant rhizome with long filiform roots, the articulated stipe, the sori that are placed in 2 irregular rows on either side of the midrib and the round to kidney shaped indusium.

Derivation

distenta: extended, stretched out; possibly referring to the widely spaced fronds on the widely creeping rhizome.

Habitat

In high rainfall areas on boulders in riverine or montane forest, sometimes scrambling in trees in evergreen forest, or as a lithophyte on rock faces on mountain peaks.

Distribution worldwide

Widespread in tropical and southern Africa.

Distribution in Africa

Angola, Burundi, Cameroon, Central African Republic, Congo, Dem. Republic of Congo, Equatorial Guinea (incl. Bioko), Ethiopia, Gabon, Ghana, Guinea, Ivory Coast, Kenya, Liberia, Malawi, Mozambique, Nigeria, Rwanda, Sierra Leone, South Africa, Sudan and South Sudan, Swaziland, Tanzania , Togo, Uganda, Zambia, Zimbabwe.

Growth form

Epiphytic, lithophytic.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 208 - 209. (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 528 - 529. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 326 - 327. (Includes a picture).
  • Kornas, J. (1979) Distribution and ecology of the Pteridophytes in Zambia. Polska Akademia Nauk Wydzial II Nauk Biologicznych. Pages 112 - 113.
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Page 142. (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 149.
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Pages 165 - 166. (Includes a picture).
  •