Fronds linear-lanceolate to lanceolate (oblong-triangular in D. goldiana), 2-pinnate, the pinnules widely attached to the costae except at the bases of the lower pinnae. Pinnules slightly, but not markedly, parallel-sided, usually somewhat tapering to their apices from ca. 2/3 their length, toothed at the sides and markedly so at the apices, usually with long acute teeth. Blade matte, herbaceous, the scales of stipe and rachis mostly lanceolate or ovate-lanceolate.

1. Blades with the lowermost pinnae shorter than those above.

2. Medium to larger ferns, more than 30 cm long.

3. Fronds spreading, blade variable, mostly ovate-lanceolate, tip of segment with acute teeth more or less pointing toward the segment apex; indusia thin and white when young, flat or slightly convex.

4. Pinnae widest at their base; indusia convex, white when young, brown when older, margins entire; pinnule toothed around apex, teeth not in pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17. D. filix-mas

4. Pinnae widest at their middle; indusia flat, white at all stages, margins lacerate; pinnule double toothed all around . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16. D. caucasica

3. Fronds erect, blade lanceolate, more narrowed at base, tip of segment with obtuse teeth pointing away from the segment apex, indusia thick and green when young, wrapping around the sori.

5. Fronds pale gray-green, to 50 cm long, stipe base scales matte, pinnule teeth spreading out in a fan-like fashion around the apex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20. D. oreades

5. Fronds yellowish-green, to 122 cm long, stipe scales glossy, pinnule teeth not spreading . . . . . . . . . . . . . . . . . . . . . 21. D. sichotensis