Dryopteris fadenii Pic.Serm.

Dryopteridaceae, JP Roux, M Shaffer-Fehre, B Verdcourt. Flora of Tropical East Africa. 2007

Type

Kenya, Naivasha/ Kiambu District, Sasumua Dam, Faden, Evans & Cameron 71/68 (Herb. Pic.Serm., holo.; BOL!, K!, Herb. Reichstein, Basel, iso.)

Morphology General Habit

Terrestrial.

Vegetative Multiplication Rhizomes

Rhizome short-decumbent, up to 16 mm in diameter, with crowded stipe bases and brown to dull ferrugineous scales, larger scales up to 31 × 5 mm, smaller scales linear-acuminate to ovate, irregularly set with short bifid teeth, glands, and irregular outgrowths

Morphology Leaves

Fronds 5–7 per plant, tufted, erect to arching, up to 1.5 m long.

Morphology Leaves Stipes

Stipe proximally castaneous, stramineous higher up, up to 61 cm long and 10 mm in diameter, near base with dense scales up to 24 × 10 mm, those higher up fugaceous.

Morphology Leaves Leaf lamina

Lamina firmly herbaceous, ovate to broadly ovate, up to 92 × 62 cm, 2pinnate to 2-pinnate-pinnatifid.

Morphology Leaves Rachis

Rachis greenish to stramineous, narrowly winged towards apex, initially with sparse to moderate stramineous to ferrugineous, scales up to 6 × 1.5 mm.

Morphology Leaves Pinnae

Pinnae up to 8 stalked pairs, subsessile and adnate towards apex, basal pinnae triangular, lanceolate, or oblong-acuminate towards lamina apex, basal pair longest, basiscopically developed, up to 32 × 14 cm; pinna-rachis narrowly winged for most of its length, subglabrous adaxially, initially moderately set with scales up to 5 × 2.5 mm on abaxial surface; pinnules petiolate, narrowly lanceolate to oblongacuminate, often slightly basiscopically developed, acroscopic pinnule on basal pinnae up to 86 × 25 mm, basiscopic pinnule on basal pinnae up to 106 × 38 mm; segments sessile, lanceolate to oblong, basiscopically decurrent, up to 18 × 8 mm, shallowly lobed to shallowly dentate, adaxially glabrous or with a few scattered hairs along costule, abaxially sparsely to moderately set with moniliform or isocytic hairs and filiform to subulate scales

Morphology Reproductive morphology Sori

Sori medial to inframedial, discrete or touching at maturity, circular, up to 2 mm in diameter; sporangium stalk simple, glandular, or with a short, few-celled hair; indusium absent or present, brown, firmly herbaceous, cordate to reniform, repand to erose, margin glandular or eglandular, up to 1 mm in diameter

Morphology Reproductive morphology Spores

Spores variously set with prominent tubercles and/or ridges, ruminate, 30–78 × 20–50 mm

Figures

Fig 13: 1

Ecology

Wet montane forests, riverine forests, streambanks, Albizia-Podocarpus forests, bamboo Podocarpus forests, giant heath zone; 1700–2500(–3500) m

Conservation

Widespread; least concern (LC)

Note

Vida, in Helv. Chim. Acta 56: 2130 (1973) report the species under the name D. pentheri as diploid: 2n = 82 ±4.

Distribution

Flora districts: U2 U4 K3 K4 K5 T2 T3 T6 T7 Range: Confined to East Africa