Clematis occidentalis, commonly known as Western Blue Virginsbower or Purple Clematis, is a deciduous vine native to the montane forests, open woodlands, and rocky slopes in the northern Rocky Mountains, extending into southern Canada and the northern United States. It typically climbs to heights of 3-9 feet (1-3 meters) and spreads 1-2 feet (0.3-0.6 meters). The vine is known for its compound leaves, each with three leaflets, and its showy single flowers with four petal-like sepals that bloom in late spring to early summer. The sepals range in color from blue-violet to pinkish-purple and are quite attractive when in bloom. After flowering, the plant produces plume-like seeds that are effectively dispersed by the wind.

Western Blue Virginsbower is valued for its ornamental flowers and can be used in gardens for vertical interest, climbing over trellises, arbors, or fences. It prefers a cool, moist root zone with well-drained soil and benefits from partial shade, especially in hotter climates. While it is not as aggressive as some other Clematis species, it requires regular pruning to maintain shape and promote vigorous growth. Gardeners should be aware that all parts of the plant are toxic if ingested and can cause skin irritation upon contact.CC BY-SA 4.0