Clematis tangutica var. tangutica

General:
Perennial vine; stems climbing or trailing on the ground, to 3 m long, sparsely soft-hairy when young.

Leaves:
Opposite, long-stalked, pinnately compound, the 5 to 7 leaflets short-stalked, lanceolate to oblong or elliptic, 2-6 cm long, 0.5-1.5 cm wide, not lobed or lobed in lower end, margins toothed, usually hairy above.

Flowers:
Inflorescence of terminal and axillary solitary flowers (occasionally 2 or 3) on stalks 0.6-3 cm long, the flowers bisexual; petals absent; sepals 4, ascending, sometimes spreading near tip, bright yellow, lanceolate to elliptic, 1.8-3.4 cm long, length about 2.5x width, margins and outside silky-hairy, smooth inside; stamens 20 to 50, filaments hairy near base; pistils 80-150.

Fruits:
Achenes, turgid, soft-hairy; beaks 2-4.5 cm long, feathery-hairy.

Source:  The Illustrated Flora of British Columbia