Species

Hymenophyllum triangulare Baker

Synonyms	Meringium triangulare (Baker) Copel. Hymenophyllum triangulare Baker subsp. ulugurense Kornas
Common name
Description	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.
Notes
Derivation	triangulare: triangular, reference to the outline of the lamina.
Habitat	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	Epiphytic.
Literature	Beentje, H.J. (2008) Hymenophyllaceae.Flora of Tropical East Africa, Page 6. Fisher E. & Killmann D. (2008) Illustrated Field guide to the Plants of Nyungwe National Park Rwanda. University of Koblenz-Landau. Pages 96 - 97. (Includes a picture). 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).