Hymenophyllum - Hymenophyllaceae

Hymenophyllum triangulare Baker






Meringium triangulare (Baker) Copel.
Hymenophyllum triangulare Baker subsp. ulugurense Kornas

Common name


Rhizome creeping, wiry, hairless or with hairs to 1.5 mm. Fronds spaced at 2–10 cm apart. Stipe (2–)4–6 cm long, unwinged or with very narrow wings, hairless or with a few hairs. Lamina triangular to oblong in outline, 7–12 x 4–6 cm, pinnae 5–8, narrowly ovate in outline, to 3 x 2.5 cm; ultimate segments linear, to 4 x 1.5 mm, rounded, margin spinulose to denticulate; glabrous. Rhachis narrowly winged, the wings with narrowly triangular lobes. Sori on the lower acroscopic lobe of the upper pinnae, 2–3 mm long, 1.5–2 mm in diameter; indusial lobes ovate or elliptic, glabrous; receptacle slightly exserted.



triangulare: triangular, reference to the outline of the lamina.


Moist or mist forest, often on ridge-tops.

Distribution worldwide

See African distribution.

Distribution in Africa

Burundi, Cameroon, Dem. Republic of Congo, Equatorial Guinea (incl. Bioko), Rwanda, Tanzania .

Growth form



  • Beentje, H.J. (2008) Hymenophyllaceae.Flora of Tropical East Africa, Page 6.
  • 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 47.
  • Tardieu-Blot, M.-L. (1964) Ptéridophytes vol.3.Flore du Cameroun, Pages 74 - 75. (Includes a picture).