Trophophore stalk 0--5 mm, to 1/6 length of trophophore rachis; blade dull, ± glaucescent green, oblong, 1--3-pinnate, to 10 × 9 cm, firm. Pinnae to 7 pairs, somewhat ascending, approximate to slightly remote, distance between 1st and 2d pinnae not or slightly more than between 2d and 3d pairs, basal pinna pair approximately equal in size and cutting to adjacent pairs, spatulate-ovate to narrowly ovate, divided to tip, ultimate segments squarish to linear, rounded to square to acute at apex, margins entire to lobed to fully dissected, apex rounded to acute, venation pinnate. Sporophores 1--3-pinnate, 1.3--2.4 times length of trophophore. 2 n =180. Leaves appearing in spring, dying in late summer. Old fields, secondary growth woods; 0--1200 m; St. Pierre and Miquelon; N.B., Nfld., N.S., Ont., Que.; Conn., Del., D.C., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.; Europe.

Plants 5-28 cm, wholly glabrous; bud with the blade bent over at the tip and clasping the erect sporophore; blade supramedial on the apparent stem, deciduous, with a 2-15 mm stalk, submembranous, oblong or ovate, mostly 1.5-7(-9) נ0.4-7(-7) cm, the pinnae 2-7 pairs, subopposite, obtuse or acutish, obtusely sublobate or in well developed plants again pinnatifid with obtusely lobed segments; sporophore 3-12+ cm, pinnate or bipinnate, its stalk 1- 4 cm; 2n=180. Thickets and rich woods in subacid soil; circumboreal, in Amer. from Nf. to Alta., s. to N.J., Md., Va., N.C., Tenn., n. O., Wis., S.D., and Colo.; Patagonia. June-Aug. Ours is var. matricariifolium. (B. neglectum; B. oblanceum; B. pseudopinnatum; B. ramosum of auth.)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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