Dryopteris lewalleana Pic.Serm.
Synonyms |
Lastrea pentagona T.Moore |
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Common name |
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Description |
Rhizome shortly-creeping, becoming erect at the growing tip, up to 160 × 25 mm; rhizome scales straw- to rust-coloured, ovate to linear-acuminate, up to 18 × 4 mm, margins entire or with a few outgrowths, apex thread-like. Fronds tufted to spaced at rhizome apex, suberect to arching, up to 1.35 m long, herbaceous. Stipe up to 67 cm long, pale brown to greenish above, chestnut-coloured below, with straw- to rust-coloured scales, ovate to narrowly lanceolate, up to 25 × 6 mm, denser near the base. Lamina up to 73 × 64 cm, ovate to deltate in outline, 3-pinnatifid to 3-pinnate, up to 14 pairs of pinnae, spaced below and somewhat overlapping near the lamina apex. Pinnae up to 32 × 25 cm, forming an angle of 70-80° from the rhachis, usually not reduced and basiscopically developed, basal pair inequilaterally triangular to deltate in outline. Pinnules: acroscopic pinnule smaller than basiscopic pinnule on basal pinnae; ultimate segments narrowly ovate-obtuse to oblong-obtuse, shallowly to deeply lobed, margins serrate, glabrous on both surfaces but with a few minute hairs and scales along the costules and costae, costules narrowly winged for most of the length. Rhachis straw-coloured with a few straw-to rust-coloured scales similar to but smaller than those on the stipe, narrowly winged towards the apex. Sori round, c. 1.6 mm in diameter, medial on the veins; indusia kidney-shaped, entire, persistent, brown, up to 1.6 mm in diameter, glabrous. |
Notes | Could be confused with Dryopteris pentheri which has basal pinnae inequilaterally ovate, with the basal basiscopic pinnule shorter than the 2 or 3 adjacent pinnules and narrowly lanceolate to filiform stipe scales. |
Derivation | lewalleana: type specimen was collected in Burundi by J. Lewalle, a Belgian botanist. |
Habitat | Seasonally moist conditions among rocks, along streams in evergreen forests, riverine forests, hillside thickets, woodland. |
Distribution worldwide | See African distribution. |
Distribution in Africa |
Burundi, Dem. Republic of Congo, Ethiopia, Kenya, Malawi, Mozambique, South Africa, Swaziland, Tanzania , Uganda, Zambia, Zimbabwe. |
Growth form |
Lithophytic, terrestrial. |
Literature |
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