Aristolochia macrophylla Lam.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - High-climbing woody twiner; lvs broadly round-cordate, 1–4 dm long and wide, glabrous, or minutely hairy beneath; peduncles solitary or few together in the axils, glabrous, very slender, bearing near the middle a cordate-clasping, foliaceous bract 1–2 cm wide; perianth glabrous, strongly bent, 4 cm, much dilated at base, gradually narrowed to the throat, the limb dark madder-purple, 2.5 cm wide, subequally 3-lobed; fr cylindric, 5–8 cm. Rich mt. woods; Appalachian region from s. Pa. to n. Ga.; cult. and escaped northward. June. (A. durior, probably misapplied)