Flower:

Cluster of 2 to 6 pink pea-shaped flowers on a slender hairy stalk arising from a leaf axil, the flower stalk longer than the adjoining leaf stalk. Only 1 or 2 flowers open at the same time, a cluster having both developing buds and mature pods present at the same time. Flowers are ¼ to 1/3 inch wide, the upper petal (standard) with a decorative eyespot at the base, the lateral wings below it curve down and up along side the lower keel, which has a dark purplish horn-like projection much resembling that of a rhinocerus.

Leaves and stem:

Leaves are compound in groups of 3, on a slender hairy stalk. Leaflets are ¾ to 1½ inches long, ¼ to ½ inch wide, oblong to lance elliptic, rounded at the base but more tapered at the tip, toothless, sparsely hairy to hairless. The middle leaflet is stalked, laterals stalkless. Stems are slender and twining, covered in short fine hairs.

Fruit:

Fruit is a slender cylindrical pod, 1 to 1¾ inches long, densely hairy when young, becoming smoother with maturity, ripening to a brownish gray with purplish marks.

Notes:

Neither Trailing Pea or the closely related Wild Bean (Strophostyles helvola) are frequently encountered in general and when you do run across them it's likely just a random plant here or there. On the site where I've encountered this species its appearance from year to year is widely scattered over the area.