2.
Osmunda claytoniana
Linnaeus, Sp. Pl. 2: 1066. 1753.
Interrupted fern, osmonde de clayton
Leaves pinnate-pinnatifid; petioles ca. 1/3 length of blades, winged, with light brown hairs, becoming glabrate. Sterile leaves elliptic to oblong, ca. 0.5--1 m; pinnae broadly oblong, lacking persistent tuft of hairs at base; ultimate segments with base truncate, margins entire, apex rounded. Fertile leaves with greatly reduced, sporangia-bearing medial pinnae that wither early, giving appearance of no middle pinnae (hence the vernacular name, interrupted fern). Sporangia greenish, turning dark brown. 2 n =44.
Sporulation early spring--midsummer; 0--2300 m; St. Pierre and Miquelon; Man., N.B., Nfld., N.S., Ont., P.E.I., Que.; Conn., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.; Asia
Osmunda claytoniana is sparingly cultivated as an ornamental.
