R & C | BOTANY | CULTIVATED DRYOPTERIS FERNS | SUBGENUS PYCNOPTERIS
Subgenus 1: Pycnopteris (T. Moore) Ching
Blade firm-textured, pinnate, the terminal segment resembling the lateral ones.
1. Dryopteris sieboldii (Van Houtte ex Mett.) Kuntze (Rev. Gen. Pl. 2: 813. 1891).--Fig. 1.
Rhizome erect, more or less stout. Stipe ca. 40 (30-60) cm long, densely scaly at the base, sparsely so above, the scales narrow triangular to ovate triangular, subentire to sparsely fimbriate or distantly dentate, dark brown, the rachis sparingly fibrillose-scaly; blade pinnate (young fronds often simple and cordate) with the apex ending in a terminal pinnae like the lateral pinnae, ca.50 cm long, 37 cm wide, pinnae pairs mostly 3 (1—5), pale green beneath, coriaceous-chartaceous; pinnae broadly linear-lanceolate, 18—30 cm long, 3.5—6 cm wide, base slightly cordate to rounded, sometimes oblique, margins slightly serrate or crenate, sometimes shallowly lobed with the lobes serrate. Sori large, in 2—3 series next to the costa, mostly absent from the marginal and submarginal area; indusia large, entire, thin.
Dryopteris sieboldii is native to eastern Asia where it is common in wooded ravines. This tetraploid, sexual species is distinct by having an apical pinna similar to the lateral ones and with few large lateral pinnae. Although slow growing in cultivation, plants may reach about 40 cm or more in height. The spreading fronds are coarse and few but tend to form a clump and could be used as an accent in the landscape. Slightly undulating and lobed margins tend to develop in cultivated plants. The plant is hardy to a winter minimum average of ca. 35°F. Semi-deciduous, nearly evergreen in southern California.
