Dryopteris Adans. section Fibrillosae Ching

Bulletin of the Fan Memorial Institute of Biology (Botany) 8: 366 (1938).

— Type: Dryopteris fibrillosa (C.B.Clarke) Hand.-Mazz., non (Baker) C.Chr. (1905: 264);

Nephrodium filix-mas (L.) Rich. var. fibrillosa C.B.Clarke (now Dryopteris pulcherrima Ching).

Aspidium Sw. subgen. Dichasium A.Braun in Flora 24: 710 (1841). — Dichasium (A.Braun) Fée, Mémoires sur la famille des fougères 5: 302 (1852). — Dryopteris Adans. subsect. Dichasium (A.Braun) H.Itô, in NAKAI & HONDA, Nova flora japonica 4: 6 [“1938”] (1939). — Type: Dryopteris fibrillosa (C.B.Clarke) Hand.Mazz., non (Baker) C.Chr. (1905: 264), now D. pulcherrima Ching.

DESCRIPTION

Rhizome short and erect to suberect, up to 150 mm tall and closely set with roots, crowded and persistent stipe bases, and scales. Fronds are 1-pinnate to 1-pinnate-pinnatisect and more or less narrow-elliptic in outline. The pinna-lobes are markedly regular and rectangular to parallelogram-shaped with truncate apices. The lobe sides are mostly shallowly lobed, but the apices are strongly toothed. The scales are chartaceous to thinly crustaceous, broadly attached or short-stalked, subulate to filiform, and the margins variously set with short and long, apically or basally directed, often branched outgrowths which reduce in number and size towards the scale apex, the apex terminates in a subulate cell or an elliptic thin-walled cell. Uniseriate hairs are absent. Sori occur medially or inframedially on predominantly anadromous vein branches, forming a single row on either side of the costa.

REMARKS

A section of about 21 species distributed throughout most of the range of the genus with the exception of North America, rare in Africa. Many of the species are thought to be derived from D. wallichiana or its relatives through hybridization with sexual diploids (Fraser-Jenkins 1986: 191). Species in the section show a high degree of chemical uniformity (Widén et al. 1996).

A single species belonging to section Fibrillosae occurs in the region.