Species

Adiantum - Adiantaceae

Adiantum incisum Forssk.

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 in outline, c. 4 mm in long and 0.2 mm wide, brown with pale margin. Fronds monomorphic, 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; pinnae numerous (up to 40 pairs), persistent, shortly petiolate or sessile, alternate, subrectangular in outline, 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; rhachis and pinnae thinly set with pale hairs. 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 , Benin , 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). Fisher E. & Lobin W. (2024) Checklist of Lycopodiopsida (clubmosses and quillworts) and Polypodiopsida (ferns) of Rwanda.Willdenowia, 53 Page 165. 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).