Ophioglossum - Ophioglossaceae

Ophioglossum gracillimum Welw. ex Hook. & Baker

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

Photo: JE. Burrows
Zimbabwe

 

 

 

 

Synonyms

Ophioglossum lusitanicum L. var. gracillinum A.Braun

Common name

Description

Rhizome spindle-shaped, c. 1-3 mm thick, 2-14 mm long, sometimes with a single, withered, persistent leaf base; roots descending, some horizontal, not proliferous. Leaves 1 or 2 (rarely 3), erect to 30° from the vertical, mid-green. Stipe up to 3 cm long, subterranean for 40-50 % of its length, stipe:lamina lenght ratio 0.6-1:1, stipe bases not persistent. Sterile lamina 16-35 × 1-2.5 mm, lenght:width ratio 10-20:1, linear-elliptic to needle-like in outline, somewhat falcate, apex with short sharp point (mucro), base narrowly tapering, sometimes into a slender pseudo-petiole, venation of c. 7 longitudinal anastomosing veins forming slender areoles. Fertile segment 2.5-4.5 cm long, inserted at the base of the lamina, fertile spike: lamina lenght ratio 1.3-2.1:1. Sporangia 7-15 pairs.

Notes

O. gracillimum has a long needle-like leaf with a width:length ratio of 1:10-20. It could be confused with O. lusoafricanum that has a more linear rhizome, a stipe that is buried for 30-50% of its length and a leaf with:length ratio of 1:7-9.

Derivation

gracillinum: slender; this species has a very narrow leaf.

Habitat

Seasonally moist, shallow sandy soils along vlei margins and watercourses, often in areas overlying sheetrock in deciduous woodland.

Distribution worldwide

See African distribution.

Distribution in Africa

Angola, Ghana, South Africa, Tanzania , Zimbabwe.

Growth form

Terrestrial.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Page 40. (Includes a picture).
  • Burrows, J.E. & Johns, R.J. (2001) Ophioglossaceae. Flora of Tropical East Africa, Royal Botanic Gardens, Kew . Page 12. (Includes a picture).
  • Burrows, J.E., Edwards, T.J. (1993) Nomenclatural changes and additions to the genus Ophioglossum in Africa (Ophioglossaceae: Pteridophyta). Bothalia, 23(2) Pages 186 - 188. (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 118 - 119. (Includes a picture).
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Pages 32 - 33.
  • 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 33.
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