Vines or vinelike caulescent herbs, biennial, perhaps also annual, from taproots. Stems developing in 2d year, climbing, usually simple. Leaves cauline, compound, petiolate; blade with 3-5 orders of leaflets and lobes; margins entire; surfaces glabrous; distal petiolules and reduced leaflets twining and tendril-like. Inflorescences axillary, cymose-paniculate, multifloral. Flowers bilaterally symmetric about each of 2 perpendicular planes; sepals caducous, peltate with attachment near base; corolla persistent, compressed-urceolate, becoming spongy; outer petals connate except at apex, base saccate, apex with erect or reflexed, ovate to deltate lobe; inner petals similar but with apical lobes connate over stigma; filaments basally connate and adnate to petals; ovary linear or narrowly oblong; style persistent; stigma ± 2-lobed. Capsules dehiscent, 2-valved. Seeds ca. 6, elaiosome absent.
e North America, Asia (Korea).
Species 2 (1 in the flora).
The Asian members of the genus usually are considered to be a distinct species, Adlumia asiatica Ohwi.