General:
Perennial vine; stems climbing to 2 m high or trailing on the ground to 5 m long.
Leaves:
Opposite, long-stalked, firm, 3-parted, the leaflets short-stalked, lance egg-shaped to triangular, 2-11 cm long, thin, not lobed or occasionally 1- to 3-lobed, margins usually entire, occasionally shallow-toothed, hairy when young, becoming smooth, tips pointed; the stalks persisting, acting as tendrils.
Flowers:
Inflorescence of nodding or inclined, solitary flowers on long, erect stalks at ends of short branches from previous year's stems, rarely terminal on long shoots of current year's stems, the flowers bisexual; petals absent; sepals 4, usually becoming wide-spreading, violet-blue to pale blue, narrowly egg-shaped, 3-6 cm long, soft-hairy, tips sharp-pointed; stamens 20-50; pistils 40-175.
Fruits:
Achenes, elliptic, soft-hairy; beaks 3-5 cm long, feathery-hairy.