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

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.

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

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

Shady banks, clearings, banks near water, ditches, mostly in forest.

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

Angola, Benin, 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.

Lithophytic, terrestrial.