Dryopteris carthusiana
Bull. Soc. Bot. France 105: 339. 1959.
Leaves monomorphic, dying in winter, 15–75 × 10–30 cm. Petiole 1/4–1/3 length of leaf, scaly at least at base; scales scattered, tan. Blade light green, ovatelanceolate, 2–3-pinnate-pinnatifid, herbaceous, not glandular. Pinnae ± in plane of blade, lance-oblong; basal pinnae lanceolate-deltate, slightly reduced, basal pinnules usually longer than adjacent pinnules, basal basiscopic pinnule longer than basal acroscopic pinnule; pinnule margins serrate, teeth spiny. Sori midway between midvein and margin of segments. Indusia lacking glands. 2n = 164.
Habitat: Swampy woods, moist wooded slopes, stream banks, and conifer plantations
Elevation: 0–1200 m
Distribution
![V2 507-distribution-map.gif](/w/images/c/ce/V2_507-distribution-map.gif)
Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Ark., Conn., Del., Idaho, Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., Wash., W.Va., Wis., Eurasia.
Discussion
Dryopteris carthusiana is tetraploid. Dryopteris intermedia is one parent, as indicated by chromosome pairing in their hybrid D. × triploidea Wherry. The other parent is the hypothetical missing ancestral species " D. semicristata " (see discussion for D. cristata). Dryopteris carthusiana hybridizes with five species; hybrids can be separated from D. intermedia by the lack of glandular hairs and by having 2-pinnate leaves.
Selected References
None.