Ophioglossum - Ophioglossaceae

Ophioglossum thomasii R.T. Clausen

Photo: JE. Burrows






Common name


Rhizome minute, ellipsoid to spindle-shaped, 1–5 mm long, 1 mm wide; roots few, horizontal, fleshy, proliferous. Leaves usually 1 (rarely 2), almost flat on the ground. Petiole 2-7 mm long, completely subterranean, petiole bases not persistent, stipe:lamina lenght ratio 1-2.3:1. Sterile lamina minute, blue-green, becoming orange-yellow with age, oblanceolate to elliptic in outline, 1–8 × 0.3–2 mm, lenght:width ratio 1.5-2.5:1, apex rounded to broadly pointed, base attenuate, margins flat; venation simple, usually one median and two lateral veins. Fertile spike 1.5–5 cm long, fertile spike:lamina lenght ratio 6.5-11:1 with 2–7 pairs of sporangia, apex pointed.


It can be distinguished from other Ophioglossum species by its small size, the smaller sterile leaf and proportionately longer fertile spike.


thomasii: probably named after H.N.Thomas, anthropologist and plant collector.


Shallow soils in marsh or seasonally wet grasland, shallow peaty soils overlying granite or quartzite in seepage zones in deciduous woodland.

Distribution worldwide

See African distribution.

Distribution in Africa

Benin, Cameroon, Dem. Republic of Congo, Gabon, Ghana, Ivory Coast, Liberia, Malawi, Nigeria, Rwanda, Tanzania , Uganda, Zambia, Zimbabwe.

Growth form



  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 47 - 48. (Includes a picture).
  • Burrows, J.E. & Johns, R.J. (2001) Ophioglossaceae. Flora of Tropical East Africa, Royal Botanic Gardens, Kew . Pages 5 - 6. (Includes a picture).
  • Fisher E. & Lobin W. (2024) Checklist of Lycopodiopsida (clubmosses and quillworts) and Polypodiopsida (ferns) of Rwanda.Willdenowia, 53 Page 155.
  • Kornas, J. (1979) Distribution and ecology of the Pteridophytes in Zambia. Polska Akademia Nauk Wydzial II Nauk Biologicznych. Page 38.
  • 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 35.
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta.Southern African Botanical Diversity Network Report, 13 Page 34.
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta.Flora Zambesiaca, 0 Page 35. (Includes a picture).
  • Thardieu-Blot, M.L. (1964) Ptéridophytes vol.8.Flore du Gabon, Page 31. (Includes a picture).