Diplazium - Woodsiaceae

Diplazium humbertii (C.Chr.) Pic.Serm.

 

 

 

 

Synonyms

Athyrium humbertii C.Chr.

Common name

Description

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.

Notes

Derivation

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

Habitat

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

Distribution worldwide

See African distribution.

Distribution in Africa

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

Growth form

Terrestrial.

Literature

  • Fisher E. & Lobin W. (2023) Synoptic Revision of Diplazium (Athyriaceae) in Rwanda with description of Diplazium cyamudongoense sp. nov..Phytotaxa, 600 (3) Page 175. (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 217.
  • Verdcourt, B. (2003) Woodsiaceae.Flora of Tropical East Africa, Pages 22 - 23.
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