Polyphlebium - Hymenophyllaceae

Polyphlebium borbonicum (Bosch.) Ebihara & Dubuisson

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

 

 

 

 

Synonyms

Trichomanes borbonicum Bosch
Crepidomanes borbonicum (Bosch) J.P.Roux
Trichomanes goetzei Hieron.
Vandenboschia borbonica (Bosch) G. Kunkel

Common name

Description

Rhizome creeping, filiform; covered with long brown unbranched hairs, hairs up to 1 mm long. Fronds spaced 1-4 cm apart. Stipe 6-30(-65) mm long, narrowly winged in distal half to three quarters, glabrous except near very base. Rhachis winged. Lamina 25-65 × 15-50 mm, ovate to narrowly lanceolate in outline, base truncate to broadly cuneate, 2- or 3-pinnatifid; pinnae 6-14 on each side, up to 3.5 x 1 cm, spreading at 45 to 90° from the rhachis; ultimate lobes linear, entire, rounded, false veins or drying fold absent. Sori borne in the upper half of the frond, indusium narrowly obconical, about twice as long as wide, narrowly winged by the lamina for its whole length, soral lips flared, receptacle exserted up to 7 mm.

Notes

A distinct form possessing much longer, branched root hairs, a semiflabbellate lamina and a false intramarginal vein occurs in Swaziland and Zimbabwe. These plants occupy a slightly drier forest type than is typical for P. borbonicum.
P. borbonicum can be seperated from C. melanotrichum and C. inopinatum by having brown rhizome hairs, a stipe that is winged in the upper half, stipe hairs and a drying fold that are absent and a sorus that is twice as long as wide.

Derivation

borbonicum: of Bourbon; this fern was first described from Bourbon, the original name for Réunion.

Habitat

Moist deeply shaded montane forest, by streams.

Distribution worldwide

Africa, Madagascar and the Mascarenes.

Distribution in Africa

Cameroon, Democratic Republic of Congo, Equatorial Guinea (incl. Bioko), Ethiopia, Ghana, Guinea, Ivory Coast, Kenya, Liberia, Malawi, Mozambique, Rwanda, South Africa, Swaziland, Tanzania , Zimbabwe.

Growth form

Epiphytic, lithophytic.

Literature

  • Beentje, H.J. (2008) Hymenophyllaceae. Flora of Tropical East Africa, Pages 26 - 27. (Includes a picture).
  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Page 93. (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 150 - 151. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 189 - 190. (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. Pages 47 - 48.
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Page 45.
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Page 76. (Includes a picture).
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