Adiantum capillus-veneris L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Rhizome short-creeping, 1.5–2.5 mm thick, its slender dark brown scales 1.5–3 mm, scarcely 0.5 mm wide; lvs scattered, lax, mostly 1–4(–5) dm overall; petiole purplish-black, nearly or fully as long as the blade; blade (once or) twice (or in part thrice) pinnate, mostly 2–4 times as long as wide; pinnae alternate, few, mostly 5–12 on each side; ultimate segments petiolulate, subflabellate or rhombic, deeply parted with dentate lobes, lacking a midrib; fertile pinnules slightly smaller than the sterile; 2n=60. Moist calcareous rocks and banks; Va., Ky., Mo., S.D., and Utah, s. to the tropics, and in warmer parts of the Old World; sometimes escaped farther north.
southen maidenhair fern