20. Dryopteris oreades Fomin (Vestn. Tiflissk. Bot. Sada 18: 20. 1910).—Mountain male fern, dwarf male fern.—Fig. 21.  

Lastrea propinqua Wollaston ex Lowe

D. abbreviata (DC) Newman, misapplied

Rhizome erect, stout, producing offshoots. Fronds stiff, erect, to ca. 70 cm long, 15 cm wide, stipe generally ca. 1/4 or less the frond length, the stipe scales moderately dense, mostly narrow to broad lanceolate, membranous, tannish;, pale gray-green, the margins crisped; blade mostly deeply pinnate-pinnatifid, to 2 pinnate at the base, mostly ovate-lanceolate, 30—50 cm long, undersurface sparsely covered with minute glands; pinnae slightly stalked, proximal pinnae triangular; pinnule (or segment) apex rounded with blunt divergent teeth often curving upwards from plane of frond. Indusia more or less thick, granular.

Dryopteris oreades is a sexual diploid species native to the British Isles, western Europe and western Asia. It is found growing in scree, rocky banks and stone walls in mountainous areas where it forms thick clumps.

The species appears like a smaller version of D. filix-mas ,but is gray-green and has sori in the distal 1/3 of the frond, the margins of the segments are crisped and most importantly the teeth at segment apex are obtuse and spreading. Dryopteris oreades lacks the dark spot on the costa at the rachis junction as in D. affinis. The characters that distinguish D. oreades from D. sichotensis are described under the latter.

Dryopteris oreades is attractive for its dense cluster of crisp-margined fronds, and young plants quickly form side crowns. It is easily cultivated, and is hardy to a January average of 30°F, deciduous. Fronds are quickly damaged under hot dry conditions.

Several cultivars are reported in cultivation by Mickel (1994) and include:

Dryopteris oreades ‘Crispa’.—Pinnae with crisped margins

Dryopteris oreades ‘Cristata’.—Pinnae crested.

Dryopteris oreades ‘Incisa Crispa’.—Pinnules incised and crisped, up to 1 cm wide.