Adiantum - Adiantaceae

Adiantum incisum Forssk.

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

 

 

 

 

Synonyms

Adiantum caudatum sensu Sim
Adiantum zollingeri sensu Garruth., non Mett. ex Kuhn
Adiantum caudatum sensu Hook.
Adiantum caudatum L. var. hirsutum (Bory) Mett. ex Kuhn
Adiantum capillus-gorgonis Webb
Adiantum radicans Fée

Common name

Description

Rhizome short, erect, up to 10 mm in diameter; rhizome scales linear, brown with pale margin, c. 4 mm in long and 0.2 mm wide. Fronds tufted, membranous to firmly herbaceous, arching. Stipe up to 8 cm long, dark brown to black, shiny, with numerous reddish brown hairs and long, linear, brown scales. Lamina pinnate, linear-lanceolate in outline;10-40 × 2-4 cm, excluding a glabrous extension of the rhachis of varying length, which often ends in a proliferous bud or lamina with a terminal pinna. Rhachis and pinnae thinly set with pale hairs. Pinnae numerous (up to 40 pairs), persistent, subrectangular, shortly petiolate or sessile, alternate; 7-23 × 4-11 mm, reduced in size towards the base and apex, the midrib forms the lower margin, outer margin irregularly incised into lobed, densely to sparsely hairy or sometimes almost without hairs, venation usually prominent. Sori on the undersurface of deflexed, membranous, oblong to lunate, glabrous or thinly hairy indusial flaps.

Notes

A. incisum is pinnate and has a hairy rhachis. It resembles A. comorense which has a longer petiolule (2-4 mm) and pinnae that are not deeply incised. It also may be confused with Lindsaea odorata, an unrelated species, which has glabrous, non proliferous fronds, a creeping rhizome and smells of almonds when crushed.

Derivation

incisum: cut-in; referring to the strongly incised pinna margins.

Habitat

Terrestrial or lithophyte, on seasonally moist earthbanks, in rock crevices, at bolder bases in deciduous woodland or riverine forest.

Distribution worldwide

Widespread in tropical Africa, also in S and SW Africa, Yemen (and India?).

Distribution in Africa

Angola, Botswana, Burundi, Ghana, Kenya, Malawi, Mozambique, Namibia, Nigeria, Rwanda, Somalia, South Africa, Sudan and South Sudan, Tanzania , Togo, Uganda, Zambia, Zimbabwe.

Growth form

Epiphytic, lithophytic, terrestrial.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Page 118. (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 424 - 425. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 223 - 224. (Includes a picture).
  • Kornas, J. (1979) Distribution and ecology of the Pteridophytes in Zambia. Polska Akademia Nauk Wydzial II Nauk Biologicznych. Pages 63 - 64.
  • 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 69.
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Page 75. (Includes a picture).
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Pages 108 - 109. (Includes a picture).
  • Verdcourt, B. (2002) Adiantaceae. Flora of Tropical East Africa, Pages 55 - 56. (Includes a picture).
  •