Azolla - Salviniaceae

Azolla pinnata R. Br. ssp. africana (Desv.) R.M.K. Saunders & K. Fowler

Photo: P. Ballings
Zimbabwe

Photo: P. Ballings
Zimbabwe

 

 

 

 

Synonyms

Azolla africana Desv.
Azollla pinnata R.Br. var. africana (Desv.) Baker
Azolla guineensis Schumach.

Common name

Description

Rhizome horizontal, branched into 3-5 alternate pinnae, up to 0.2 mm in diameter, with roots single or in fascicles of 2-3 at the branche nodes, up to 3.5 cm long, hairy, with conspicuous root cap. Leaves minute in 2 rows, 2-lobed, dark green; upper lobe ovate to broadly elliptic in outline, apex pointed, margin translucent, up to 1.1 mm long, papillate in the centre; lower lobe more or less equal in size, colourless. Plant heterosporous, sporocarps on the submerged lower lobes of the leaves.

Notes

It can be distinguished from A. filliculoides by its somewhat smaller size, hairy roots and clearly pinnate branching structure. A. nilotica differs from A. pinnate in having numerous (5 or more) roots per node (not 2-3) and in being larger and more branched.

Derivation

pinnata: with pinnate leaves, refers to the distinctly pinnate arrangements of the branches of the stem.

Habitat

Forms dense mats on shallow water or lakes, ponds, backwaters of rivers, papyrus swamps, neglected paddy fields.

Distribution worldwide

Africa, Madagascar, New Guinea, Australia.

Distribution in Africa

Angola, Benin, Botswana, Burkina Fasso, Burundi, Cameroon, Chad, Ethiopia, Gambia, Ghana, Guinea Bissau, Kenya, Liberia, Mali, Mozambique, Rwanda, Senegal, Sierra Leone, Sudan and South Sudan, Tanzania , Uganda, Zambia, Zimbabwe.

Growth form

Aquatic.

Literature

  • Burrows, J.E. (1990) Southern African Ferns and Fern Allies. Frandsen, Sandton. Pages 81 - 82. (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 212 - 214. (Includes a picture).
  • Jacobsen, W.B.G. (1983) The Ferns and Fern Allies of Southern Africa. Butterworths, Durban and Pretoria. Pages 493 - 494. (Includes a picture).
  • Kornas, J. (1979) Distribution and ecology of the Pteridophytes in Zambia. Polska Akademia Nauk Wydzial II Nauk Biologicznych. Page 123.
  • Roux, J.P. (2001) Conspectus of Southern African Pteridophyta. Southern African Botanical Diversity Network Report, 13 Page 179.
  • 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 59.
  • Schelpe, E.A.C.L.E. (1970) Pteridophyta. Flora Zambesiaca, 0 Pages 69 - 70.
  • Verdcourt, B. (1999) Azollaceae. Flora of Tropical East Africa, Pages 1 - 2.
  •