General:
Perennial woody vine from a rhizome; stems clambering or climbing, generally to 6 m long (up to 20 m), nearly smooth to densely short stiff-hairy or long soft-hairy; dioecious.
Leaves:
Opposite, pinnately compound, the 5 to 7 leaflets stalked, broadly egg- to lance-shaped, 3-9 cm long,1-7 cm wide, lobed or not, margins entire to coarsely few-toothed, smooth or sparsely soft-hairy on upper surfaces, especially on veins; the stalks persisting, acting as tendrils.
Flowers:
Inflorescences axillary, compound cymes of 7 to 20 flowers on current year's stems, the flowers crowded, unisexual; flower stalks slender, 0.5-3 cm long; petals absent; sepals 4, wide-spreading, white to cream, egg-shaped to oblanceolate, 6-10 mm long, soft-hairy; stamens 25-50, pistillate flowers with sterile stamens; pistils 25-65, staminate flowers without vestigial pistils.
Fruits:
Achenes, elliptic, 3-3.5 mm long, about 1.5 mm wide, silky-hairy; beaks 3-3.5 cm long, feathery-hairy.
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Synonyms and Alternate Names:
Clematis neomexicana Woot. & Standl.
Clematis suksdorfii B.L. Rob.
KEY TO CLEMATIS
1. Sepals blue to reddish purple......................................C. occidentalis 1. Sepals bright yellow to cream or white. 2. Sepals white; flowers imperfect; the plants dioecious, plants native.....................................C. ligusticifolia 2. Sepals bright yellow or cream, if white then the flowers perfect; plants introduced. 3. Sepals bright yellow..........................................C. tanguitica 3. Sepals cream or white.....................................C. vitalba |