Pteris - Pteridaceae

Pteris burtonii Baker

 

 

 

 

Synonyms

Pteris johnstonii Baker
Pteris aethiopica H. Christ.
Pteris atrovirens Willd. var. cervonii Bonap.
Pteris burtonii Bak. var. aethiopica (H. Christ.) Tardieu

Common name

Description

Rhizome erect or ascending; rhizome scales lanceolate to linear-lanceolate in outline, 3–4 mm long, narrowly dark in the middle with pale edges. Fronds (1–)few, tufted, 0.3–1 m tall. Stipe 10–38 cm long with scales near base. Lamina triangular, 20–40 x 15–40 cm wide with a gemma near the base of the terminal pinna. Pinnae in 1–5 pairs, typically (but apparently not in E Africa) the pinnae simple, 6–19 x 1.4–4 cm, entire or with a few coarse lobes and basal pair with a basiscopic spur; more usually the pinnae are deeply pinnatifid and in W Africa simple and pinnatifid fronds often occur on the same plant with every intermediate; pinnae oblong-lanceolate in outline, 13–22 x 3–8 cm, the terminal segments narrowly triangular-lanceolate, 3–6(–9) x 1 cm, crenulate at the apex; ultimate segments of pinnae in 10–15 pairs, oblong in outline, 0.6–4.5 x 0.5–1.1 cm, ± rounded and crenate-serrate at the apex, the basal basiscopic segment of lowest pinnae much longer, 7.4 x 1.4 cm; costa of pinnae ± smooth on both sides save for very sparse roughening and a small patch of dense short emergences where base of pinna meets the rhachis; rhachis narrowly winged by decurrent pinna bases; veins in segments usually densely anastomosing. Sori often running along whole margin of pinna whether simple or deeply pinnatifid without a gap in sinuses and then up to 20 cm long, but tips of ultimate segments usually sterile and crenate and sori usually U-shaped and 2–5 cm long.

Notes

Derivation

burtonii: named after Mr. Burton who first collected this fern in Ghana.

Habitat

Moist slopes on forest near river.

Distribution worldwide

See African distribution.

Distribution in Africa

Angola, Burundi, Cameroon, Central African Republic, Congo, Dem. Republic of Congo, Equatorial Guinea (incl. Bioko), Gabon, Ghana, Guinea, Ivory Coast, Liberia, Nigeria, Sierra Leone, Tanzania , 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 170.
  • Verdcourt, B. (2002) Pteridaceae. Flora of Tropical East Africa, Pages 10 - 11.
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