Equisetum sylvaticum
Sp. Pl. 2: 1061. 1753.
Aerial stems dimorphic; vegetative stems brownish to green, branched, 25–70 cm; hollow center 1/6–1/3 stem diam. Sheaths squarish in face view, 3–6 × 2.5–6 mm; teeth reddish, 8–18, papery, 3–10 mm, coherent in 3–4 large groups. Branches in regular whorls, delicate, arching, branched, solid; ridges 3–4; valleys channeled; 1st internode of each branch longer than subtending stem sheath; sheath teeth attenuate. Fertile stems brown, with stomates, initially unbranched, persisting and becoming branched and green after spore discharge. 2n =216.
Habitat: Moist forests
Elevation: 0–2800 m
Distribution
Greenland, St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Sask., Yukon, Alaska, Conn., Del., Idaho, Iowa, Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.Dak., Ohio, Pa., R.I., S.Dak., Vt., Va., Wash., W.Va., Wis., Europe, n Asia to ne China, Japan in Hokkaido.
Discussion
Selected References
None.