Athyrium humbertii C.Chr.

Rhizome ascending, thick, fleshy, up to 7 cm in diameter, elongate; rhizoma scales linear in outline, apex not filiform, margin entire, 7–23 x 1.5–2 mm, reticulate, dark chestnut and mostly black-edged. Fronds monomorphic, tufted, 1.3–1.5 m tall, sometimes gemmiferous in upper axils. Stipe 30–112 cm long, greyish straw-coloured, deeply tri-grooved above, with dense scales at base but ± glabrous. Lamina bipinnate-pinnatifid to virtually tripinnate with decurrent secondary pinnules, triangular-ovate in outline, up to 1 x 0.8 m; pinnae in ± 16 pairs, oblong-lanceolate in outline, (8–)35–42 x (3–)14–18.5 cm, with stalks 1–2 cm long and 10–16 pairs of pinnules; pinnules oblong in outline, (1–)4–10 x (0.5–)1.2–5 cm; lobes 9–12 pairs, narrowly oblong-lanceolate to oblong, margin mostly deeply crenate-lobed (up to ± 3 mm) but lobes on apical pinnules and towards apex of basal pinnules are ± entire, 0.8–2.5 x 3–7 mm; rachis straw-coloured. Sori 1–18 per pinnule lobe (one at base of each secondary lobe of the lobe), almost round to elliptic, 1–1.5 mm long; paraphyses dense; indusium covering and attached all round the sorus, bursting irregularly into lobes and leaving a cup and remnants or dorsally dehiscent.

humbertii: this fern was first collected in DRC in the mountains W of Lake Kivu by Dr. Humbert.

Lower montane forest, bamboo forest and mist forest, in swampy places and by rivers.

See African distribution.

Burundi, Dem. Republic of Congo, Rwanda, Tanzania , Uganda.

Terrestrial.