Vicia americana var. americana
This delicate vine with intensely purple flowers climbs exuberantly over grassy slopes. It puts on a solo performance as it often flowers after the showy displays of our spring wildflowers. The vetch flower is typical of the papilionoid subfamily of legumes. The two lower petals in each flower are fused into a keel. The two lateral petals are called wings. The broad uppermost petal is called the banner. The stamens and pistil are obscured by the folded keel. When a heavy bee seeking nectar lands on the flower, the keel bends downward and pollen is brushed onto the bee's abdomen. As the bee manipulates another flower in the same manner it deposits its pollen load on a receptive stigma.
DISTRIBUTION: Disturbed areas and moist forests often along streams throughout the Great Basin and Calif. Floristic Provinces; < 2400 m.