Hypodematium - Dryopteridaceae

Hypodematium crenatum (Forssk.) Kuhn

Photo: JE. Burrows
South Africa

 

 

 

 

Synonyms

Aspidium odoratum Bory ex Willd.
Cystopteris odorata (Bory ex Willd.) Desv.
Nephrodium crenatum (Forssk.) Baker
Dryopteris crenata (Forssk.) Kuntze
Lastrea hirsuta (D.Don) Moore

Common name

Description

Rhizome shortly creeping, up to 3 cm in diameter; rhizome scales dense, golden brown to rust coloured, concolorous, lanceolate-acuminate in outline, margin entire, c. 1 cm long. Fronds tufted, arching, herbaceous. Stipe up to 20 cm long, straw-coloured, glabrous except for a dense tuft of scales similar to those on the rhizome at the base. Lamina up to 33 x 30 cm, ovate-triangular in outline, up to 4-pinnatifid at the base with the basal pinnae basiscopically developed. Pinnae up to 22 cm long, oblong-acute in outline towards the apex, unequally triangular-ovate at the base. Pinnules thinly hairy on both surfaces, margins lobed to sometimes toothed. Rhachis strawcoloured, with long soft hairs. Sori round, up to 12 per pinnule , 1–1.5 mm in diameter; indusium kidney-shaped, with straight white unicellular hairs.

Notes

Might be confused with Davallia chaerophylloides. This however has a widely creeping rhizome, pinnae that are weekly basiscopicly developed and glabrous, the sori are situated at the lope tips on the pinnules. Other Dryopteris species are more or less glabrous and have hairless indusia.

Derivation

crenatum: crenate, referring to the shallow, rounded teeth of the pinnule margins.

Habitat

Rocky places in bushland; crevices in vertical dolomite rock faces, in soil at the base of rocky outcrops and cliffs, in light shade or sun.

Distribution worldwide

Africa, Madagascar, Mauritius, southern Asia to Nepal, Japan, Malaysia, Sumatra, Pacific Islands.

Distribution in Africa

Angola, Angola, Congo, Dem. Republic of Congo, Ethiopia, Kenya, Mozambique, South Africa, Sudan and South Sudan, Zambia.

Growth form

Lithophytic, terrestrial.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 320 - 322. (Includes a picture).
  • Crouch, N.R., Klopper, R.R., Burrows, J.E. & Burrows, S.M. (2011) Ferns of Southern Africa, A comprehensive guide. Struik Nature. Pages 492 - 493. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 451 - 452. (Includes a picture).
  • Kornas, J. (1979) Distribution and ecology of the Pteridophytes in Zambia. Polska Akademia Nauk Wydzial II Nauk Biologicznych. Pages 105 - 106.
  • 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.
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Page 140.
  • Roux, J.P.; Shaffer-Fehre, M. & Verdcourt, B. (2007) Dryopteridaceae. Flora of Tropical East Africa, Page 19. (Includes a picture).
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Page 230. (Includes a picture).
  •