Pteris - Pteridaceae

Pteris atrovirens Willd.

Photo: BT. Wursten
Dem. Republic of Congo

Photo: BT. Wursten
Dem. Republic of Congo

 

 

 

 

Synonyms

Pteris atrovirens Willd. var. inermis Bonap.
Pteris spinulifera Schumach.

Common name

Description

Rhizome shortly creeping; rhizome scales lanceolate in outline, 4 mm long with ± black narrow central stripe and pale margins. Fronds tufted, 0.25–1 m tall, usually without gemmae. Stipe 20–50 cm long, straw-coloured, often reddish at the base. Lamina elliptic-lanceolate, 20–50 x 15–60 cm, with (1–)5–7 pairs of pinnae, the basal pair bifid. Pinnae oblong, 13–34 x 3–7 cm, divided into 10–21 pairs of oblong-falcate ultimate segments 1.2–6.5 x 0.4–1.5 cm; terminal segments 4.5–9 x 1–1.3 cm; costa and costulae spinulose beneath or not; rhachis mostly smooth but sometimes feebly muriculate; groups of small tubercles in axils of pinnae near rhachis; veins anastomosing in the lobes and forming narrow areoles along the costae of the pinnae. Sori reaching nearly to apex of lobes, the sterile tips toothed; paraphyses mostly present.

Notes

Derivation

Habitat

Rain forest, forest stream banks, streams through limestone outcrops, moist lowland evergreen forest.

Distribution worldwide

Africa, Principe, Sao tomé.

Distribution in Africa

Angola, Benin, Burundi, Cameroon, Central African Republic, Congo, Dem. Republic of Congo, Equatorial Guinea (incl. Bioko), Gabon, Ghana, Guinea, Guinea Bissau, Ivory Coast, Kenya, Liberia, Nigeria, Sierra Leone, Sudan and South Sudan, Tanzania , Togo, Uganda.

Growth form

Terrestrial.

Literature

  • 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 169. Forma atrovirens and forma laevicosta are distinguished.
  • Verdcourt, B. (2002) Pteridaceae. Flora of Tropical East Africa, Pages 13 - 14. Forma atrovirens and forma laevicosta are distinguished.
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