Roots thick and fleshy, fusiform, fasciculate. Stem twining, 4–8 ft. long, very slender, glabrous. Leaves widely spreading; petiole 2–4 lin. long; blade 1–2 1/4 in. long, 1 3/4–3 lin. broad, linear-lanceolate, acute or obtuse, mucronulate, rounded and subpeltate at the base, glabrous, with narrowly revolute sparsely and minutely scabrid margins; peduncles 3–9 lin. long, 1–2-flowered, glabrous; flowers 1/2–1 1/2 lin. apart; bracts minute; pedicels 2 1/2–3 lin. long, glabrous. Sepals 1 1/4 lin. long, lanceolate-attenuate, glabrous. Corolla straight; tube 4 1/2–5 lin. long, 1 1/2 lin. in diam. at the ovoid-inflated base, cylindric above and scarcely widened at the mouth, which is 1 1/4–1 1/3 lin. in diam., glabrous and minutely papillate-rugulose outside, glabrous within; lobes 2 lin. long, 1–1 1/4 lin. broad, erect, connate at the tips, narrowly elliptic-lanceolate, replicate (with apparently involute margins), fringed with long hairs along the narrow keel on the face. Outer coronal-lobes very deeply bifid, forming 10 obliquely deltoid teeth 1/2 lin. long adnate to the base of the inner coronal-lobes, reaching to or above the level of the anthers, fringed with rather long hairs; inner coronal-lobes 3/4 lin. long, connivent-erect, linear, glabrous. Follicles 4 1/2 in. long, slender, terete-attenuate, divergent-reflexed, glabrous.
