Dryopteris - Dryopteridaceae

Dryopteris katangaensis J.P. Roux

 

 

 

 

Synonyms

Common name

Description

Rhizome short, erect, up to 12 mm in diameter, set with roots; rhizome scales dull brown to rust coloured, texture papery, linear, truncate to cordate, margins wavy to irregularly toothed, irregularly set with long flagelliform outgrowths, twisted, the apex flagelliform, twisted, to 23 × 3 mm. Fronds tufted, up to 5 per plant, suberect to arching, to 94 cm long. Stipe pale green, drying straw coloured, up to 49 cm long, to 9 mm in diameter, proximally adaxially flattened, shallowly sulcate higher up, densely scaled near base, moderately scaled higher up, the scales like rhizome scales but lanceolate-caudate in outline, and to 20 × 3 mm. Lamina firmly herbaceous, ovate to broadly ovate in outline, to 3-pinnate, up to 46 × 33 cm, with up to 10 pairs of pinnae. Pinnae stalked, the stalk up to 9 mm long, the basal pair inequalaterally narrowly ovate in outline, to 2-pinnate, pinnae higher up lanceolate to oblongacuminate in outline, basiscopically developed, up to 24 × 13.5 cm, opposite to alternate, spaced or overlapping, with up to 10 pairs of pinnules. Pinnules stalked, the stalk up to 3 mm long, upper surface hairless, lower surface sparsely set with hairs and scales, the hairs occurring along the costa and veins, up to 0.65 mm long, the scales straw coloured, papery to membraneous, linear to narrowly lanceolate-caudate in outline, to 3.5 × 0.35 mm. Venation pinnately branched, forked or simple near the apex, evident, ending in the teeth near the margin. Rhachis straw coloured, shallowly grooved on the upper surface, narrowly winged in the pinnatifid apex, initially moderately scaled, the scales essentially similar to those on the stipe, to 6 × 1.5 mm; costae like rhachis but scales smaller to 4 × 0.8 mm. Sori circular, inframedial on the vein branches, discrete or paired, the paired ones touching at maturity. Indusium brown to rust coloured, persistent, firmly papery, reniform, the margins strongly revolute, entire, up to 2 mm in diameter.

Notes

Derivation

katangaensis: reference to the Katanga region extending from Zambia to DRC.

Habitat

Shaded streambanks in Brachystegia–Jubernardia– Isoberlina ‘miombo’ woodland.

Distribution worldwide

See African distribution.

Distribution in Africa

Dem. Republic of Congo, Zambia.

Growth form

Terrestrial.

Literature

  • Roux, J.P. (2003) A new Dryopteris (Pteropsida: Dryopteridaceae) species from south-central Africa. Botanical Journal of the Linnean Society, 142 Pages 237 - 242. (Includes a picture).
  • Roux, J.P. (2012) A revision of the fern genus Dryopteris (Dryopteridaceae) in sub-Saharan Africa. Phytotaxa, 70(1) Pages 62 - 63. (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 122.
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