Species

Pityrogramma - Pteridaceae

Pityrogramma argentea (Willd.) Domin

Photo: P. Ballings
Mozambique

Synonyms	Gymnogramma argentea (Willd.) Mett. ex Kuhn
Common name
Description	Rhizome short, c. 2 mm in diameter, erect to procumbent; rhizome scales linear attenuate, brown. Stipe up to 30 cm long, castaneous, glabrous with few scales near the base. Fronds tufted, arching, herbaceous. Lamina ovate-triangular in outline, up to 30×25 cm, 3- to 4- pinnatifid, basal pinnae basiscopically developed, upper surface green & glabrous, under surface covered with a yellow or white powder; ultimate pinnules deeply pinnatifid into rounded lobes, margins entire or shallowly lobed; veins free. Rhachis and secondary rhachis dark brown, shiny, occasionally with some patches of yellow or white powder. Sori linear, up to 2 mm long, exindusiate, along flabellate veins on secondary pinnules.
Notes	The yellow or white powder on the undersurface of the pinnae makes this fern easy to recognize. P. calomelanos var. aureoflava also has yellow powder covering the lamina below; this species however is less divided (2- or 3-pinnatifid), more robust and the lamina is ovate to lanceolate in outline.
Derivation	argentea: silvery; refers to the white powder on the underside of the frond.
Habitat	In rock crevices and around boulders.
Distribution worldwide	Africa, Madagascar, Mauritius, Réunion.
Distribution in Africa	Angola , Malawi , Mozambique , South Africa , Zambia , Zimbabwe .
Growth form	Lithophytic, terrestrial.
Literature	Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 115 - 116. (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 312 - 313. (Includes a picture). Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 221 - 222. (Includes a picture). Kornas, J. (1979) Distribution and ecology of the Pteridophytes in Zambia. Polska Akademia Nauk Wydzial II Nauk Biologicznych. Page 61. Roux, J.P. (2001) Conspectus of Southern African Pteridophyta.Southern African Botanical Diversity Network Report, 13 Page 57. 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 177. Schelpe, E.A.C.L.E. (1970) Pteridophyta.Flora Zambesiaca, 0 Pages 105 - 107. (Includes a picture).