Polystichum - Dryopteridaceae

Polystichum volkensii (Hieron.) C.Chr.

 

 

 

 

Synonyms

Aspidium volkensii Hieron.
Polystichum barbatum C.Chr.

Common name

Description

Rhizome short, erect, up to 1 cm in diameter; rhizome scales persistent, papery, reddish, narrowly lanceolate in outline, up to 15 mm long. Fronds tufted, up to 8 per plant, erect, up to 120 cm long, herbaceous, gemmiferous. Stipe reddish-brown at base, straw-coloured above, up to 10–52 cm long, to 1 cm in diameter, upper surface grooved, stipe bases persistent, with dense reddish translucent shortly stalked scales, the larger elliptic to ovate, up to 34 x 10 mm, the smaller convolute, ovate. Lamina upper surface olive green, lower surface pale green, narrowly ovate in outline, up to 93 cm long, 3-pinnate. Pinnae oblong-attenuate, slightly falcate, basal pinnae up to 54 mm long, middle pinnae to 190 x 40 mm, lowest acroscopic pinnule slightly enlarged, a single pair of basal pinnae decrescent, often somewhat deflexed. Pinnules asymmetric, wedge-shaped, ovate, up to 23 x 11 mm, acroscopic margin auriculate, deeply lobed, lobes oblong, serrate to crenate, upper surface with few folded, filiform scales up to 15 mm long, lower surface covered with red to reddish-brown papery folded filiform scales up to 16.5 mm long. Rhachis straw-coloured, upper surface grooved, with dense often folded scales up to 18 x 6 mm, smaller than, but resembling those of, the stipe, and with a single gemmiferous bud, covered in scales, near apex. Costa straw-coloured, upper surface with groove, scales dense, similar to but smaller than those on rhachis. Sori medial on unabbreviated vein branches, mostly in 1 row, discrete at maturity, in excess of 1 mm in diameter; indusium reddish to reddish-brown, peltate, circular, elliptic or without a clearly defined shape.

Notes

Derivation

volkensii: after G.L.A. Volkens (1855-1917), German botanist and traveller, assistant of A. Engler at the Botanical Museum in Berlin, Curator of the Botanical Gardens in Berlin.

Habitat

Upper moist forest zone, Hagenia zone, giant heath zone, 2800-3600 m.

Distribution worldwide

See African distribution.

Distribution in Africa

Kenya, Tanzania .

Growth form

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 139.
  • Roux, J.P.; Shaffer-Fehre, M. & Verdcourt, B. (2007) Dryopteridaceae. Flora of Tropical East Africa, Pages 27 - 29. (Includes a picture).
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