Pityrogramma - Pteridaceae

Pityrogramma calomelanos (L.) Link var. calomelanos

Photo: BT. Wursten
Dem. Republic of Congo

Photo: BT. Wursten
Dem. Republic of Congo

Photo: BT. Wursten
Dem. Republic of Congo

 

 

 

 

Synonyms

Acrostichum calomelanos L.
Gymnocarpa calomelanos (L.) Kaulf.
Pityrogramma insularis Domin
Gymnogramma ochracea sensu Sim

Common name

Description

Rhizome erect to shortly creeping, up to 10 mm in diameter; scales light brown, linear, up to 4 mm long, margins entire. Fronds tufted, arching, firmly herbaceous. Stipe 6-36 cm long, black to chestnut brown, shiny smooth with few scales at the base. Lamina 14-37 × 7-14 cm, ovate to lanceolate in outline, 2- to 3-pinnatifid, long tapering to the apex. Pinnae oblong-lanceolate to narrowly lanceolate, pinnatifid to varying degree, apices acute, margins shallowly toothed and inrolled in dried material, dark green above and covered with a white powder below, glabrous on both surfaces. Rhachis black to chestnut brown, shiny, glabrous. Sori about 3 mm long, situated along the veins in the outer half of the lamina between the costule and margin, often difficult to see because of the yellow powder; exindusiate.

Notes

Could be confused with P. argentea but the latter has more delicate and more divided (3- or 4-pinnatifid, broadly ovate to triangular fronds.

Derivation

calomelanos: beautifully black, referring to the colour of stipe and rhachis

Habitat

May be confused with C. interruptus which has less veins per lobe (6-13) and pinnae that are incised only half way to the costa.

Distribution worldwide

Introduced from Tropical America. Found Africa, Malagasy and on the Comoro islands.

Distribution in Africa

Angola, Burkina Fasso, Burundi, Cameroon, Congo, Dem. Republic of Congo, Equatorial Guinea (incl. Bioko), Gabon, Ghana, Guinea, Ivory Coast, Kenya, Liberia, Mozambique, Nigeria, Rwanda, Senegal, Sierra Leone, Somalia, Tanzania , Uganda.

Growth form

Lithophytic, terrestrial.

Literature

  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Page 222.
  • 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 107 - 108.
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