rootstock tuberous; stem slender, twining, minutely puberulous; leaves distant, spreading; petiole 1–2 lin. long; blade 2/3–1 1/2 in. (1 1/2–2 1/2 in. ex Oliver) long, 3 1/2–7 lin. broad, oblong-obovate, obtuse, shortly apiculate, thinly puberulous above, softly pubescent beneath; cymes from one axil, few-flowered; peduncle and branches of the cyme each about 2–3 lin. long, pubescent; bracts 1/2– 2/3 lin. long, ovate, acute, brown, pubescent; pedicels 1 1/2–2 lin. long, pubescent; sepals 1 lin. long, 2/3– 3/4 lin. broad, ovate, acute, pubescent; corolla about 1 in. in diam., minutely pubescent outside, glabrous within, green; tube about 3 lin. long and broad, campanulate, internally with 5 decurrent broadly 2-winged nectaries alternating with the stamens; lobes ascending, 5–6 lin. long, 2 1/2–3 lin. broad, ovate-oblong, obliquely subemarginate at the obtuse apex, strongly revolute along the margins; corona-lobes inserted at the sinuses of the corolla, very broad at the base, and laterally adnate to the base of the corolla-lobes, 3-fid; lateral teeth about 1/2 lin. long, deltoid-oblong, obtuse, incurved, middle tooth 2 lin. long, subulate, incurved over the anthers; staminal filaments 2/3 lin. long; anthers 1 3/4–2 lin. long, oblong, apiculate, connivent and connate at the tips; pollen-carriers 1 1/2 lin. long; blade broadly ovate or cordate, obtuse; stalk slender, dilated towards the base; gland large, rectangular; style broadly and obtusely conical at the apex, shorter than the anthers. null