Rhizome ±ascending or erect; lvs evergreen; petiole, rachis, costae, and indusia bearing minute stalked glands; petiole 1-3 dm, its broad, pale brown scales with an irregular darker area; blade 2-5 נ1-2 dm, broadest just above the obtuse base, abruptly tapered below the acuminate tip, bipinnate-pinnatifid to tripinnate-pinnatifid, the lowest pinnae usually with the lowest pair of pinnules shorter than the next pair, the lowest basal pinnule only slightly or not at all larger than the subopposite acroscopic one, the ultimate segments finely spinulose-toothed; sori midway between the midvein and the margins of the ultimate segments; 2n=82. Moist woods and swamps; Nf. to Ga., w. to Minn. and Ark. (D. austriaca var. i.; D. spinulosa var. i.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.