Dryopteris - Dryopteridaceae

Dryopteris pentheri (Krasser) C. Chr.

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

 

 

 

 

Synonyms

Dryopteris inaequalis sensu Schelpe

Common name

Description

Rhizome creeping, becoming erect at the growing tip, up to 300 × 30 mm; rhizome scales straw- to rust-coloured, narrowly ovate to linear-oblong, up to 37 × 6 mm, margins with long twisted outgrowths, apex thread-like, twisted. Fronds tufted to closely spaced at rhizome apex, erect to arching, up to 1.8 m long, herbaceous. Stipe up to 49 cm long, pale brown above, chestnut-coloured below, with straw- to rust-coloured scales, thread-like to narrowly lanceolate, up to 40 × 7 mm, denser near the base. Lamina up to 78 × 64 cm, ovate to triangular in outline, 3-pinnatifid to 3-pinnate, up to 16 pairs of pinnae, spaced below and somewhat overlapping near the lamina apex. Pinnae up to 32 × 19 cm, forming an angle of 70-80° from the rhachis, usually not reduced and basiscopically developed, basal pair inequilaterally ovate to narrowly ovate in outline. Pinnules: basiscopic pinnule shorter than the 2-3 adjacent pinnules on basal pinnae; ultimate segments ovate to oblong-obtuse, lobed, margins serrate, glabrous on both surfaces but with a few minute hairs and scales along the costules and costae, costules narrowly winged for most of the length. Rhachis straw-coloured with a few straw-to rust-coloured scales similar to but smaller than those on the stipe, narrowly winged towards the apex. Sori round, c. 1.8 mm in diameter, medial on the veins; indusia kidney-shaped, margin entire or wavy, persistent, pale brown, up to 1.6 mm in diameter, glabrous.

Notes

Could be confused with Dryopteris lewalleana which has basal pinnae inequilaterally triangular to deltate, with the basal basiscopic pinnule the longest and ovate to narrowly lanceolate stipe scales.

Derivation

pentheri: named after Arnold Penther (1865-1931)

Habitat

Light shade in scrub, forest edge, among rocks in grassland or in montane boulder scree.

Distribution worldwide

Southern subtropical Africa, tropical Africa, also known from SaonTomé and Madagascar.

Distribution in Africa

Burundi, Cameroon, Democratic Republic of Congo, Equatorial Guinea (incl. Bioko), Ethiopia, Guinea Bissau, Kenya, Lesotho, Liberia, Malawi, Mozambique, Nigeria, Rwanda, Sierra Leone, South Africa, Sudan and South Sudan, Swaziland, Tanzania , Uganda, Zambia, Zimbabwe.

Growth form

Lithophytic, terrestrial.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Page 302. Treated under the Dryopteris inaequalis complex
  • Crouch, N.R., Klopper, R.R., Burrows, J.E. & Burrows, S.M. (2011) Ferns of Southern Africa, A comprehensive guide. Struik Nature. Pages 478 - 479. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 435 - 438. Treated under the Dryopteris inaequalis complex (Includes a picture).
  • Kornas, J. (1979) Distribution and ecology of the Pteridophytes in Zambia. Polska Akademia Nauk Wydzial II Nauk Biologicznych. Pages 108 - 109. Treated under the Dryopteris inaequalis complex
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Pages 125 - 126. (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 123.
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Pages 221 - 222. Treated under the Dryopteris inaequalis complex
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