Dryopteris - Dryopteridaceae

Dryopteris amblyodonta J.P.Roux

 

 

 

 

Synonyms

Common name

Description

Rhizomes suberect to short-creeping, to 10 mm in diameter, closely set with roots, persistent stipe bases and scales; rhizome scales reddish brown, matt, thin, linear in outline, apex tapering to a point, to 18 × 2 mm, truncate to cordate, mostly with marginal outgrowths on the lower part and also with a few scattered glands along the scale margin, margin entire to irregularly toothed towards the apex, the scale apex flagelliform. Fronds crowded, suberect, to 64 cm long. Stipe chestnut to brown, to 395 mm long, to 5 mm in diameter, with scales similar to those on the rhizome, but slightly smaller and mostly with more marginal outgrowths. Lamina lanceolate to ovate in outline, to 44.5 × 25.5 cm, to 2-pinnate-pinnatifid, with up to 11 pinna pairs, the distal pinnae become sessile and eventually adnate and increasingly basiscopically decurrent. Pinnae petiolate, the petioles to 10 mm long, the basal pinna pair longest or slightly shorter than the pinna pair above, to 1-pinnate-pinnatifid, the basal pinnae to 17.2 × 7.6 cm, basiscopically developed, inaequilaterally narrowly triangular, pinnae higher up symmetric or not conspicuously basiscopically developed, narrowly triangular to oblong-acuminate, with up to 6 petiolated pinnule pairs. Pinnules petiolate, the petioles to 2 mm long, firmly herbaceous, pinnatifid, lobed towards the apex, narrowly triangular, ovate, or oblong-acute in outline. Ultimate segments sessile, to 8 × 5 mm, broadly ovate-obtuse in outline, toothed, hairless or sparsely set with glands along and between the vein. Venation with lateral veins in the pinnule lobes once or twice forked, ending in the teeth near the margin. Rhachis, pinna-rhachises and costae sparsely set with glands and filiform scales. Sori essentially in 2 rows on each pinnule, medial to inframedial, more or less restricted to the anadromous vein branch of each segment or lobe, to 1.2 mm in diameter; indusia firmly herbaceous, to 1 mm in diameter, reniform, glabrous or glandular along the margin, rarely also haired.

Notes

Derivation

ambly: blunt, donta: teeth; a reference to the obtuse tetth of this species

Habitat

Doloritic rocks and cliff faces, epiphyte in dense shade along streams.

Distribution worldwide

See African distribution.

Distribution in Africa

Sierra Leone.

Growth form

Epiphytic, lithophytic, terrestrial.

Literature

  • 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 120.
  • Roux, J.P. (2012) A revision of the fern genus Dryopteris (Dryopteridaceae) in sub-Saharan Africa. Phytotaxa, 70(1) Pages 26 - 27. (Includes a picture).
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