Vicia villosa ssp. villosa

Native to Western Asia and Europe. Introduced and widely naturalized throughout North America.

Invasive

Fields, disturbed sites.

June to August

Purple

Trailing or climbing, 12″ to 36″ long

This is a trailing or climbing annual or biennial forb that rises from a 12″ to 36″ long taproot and spreading rhizomes. It often forms colonies.

The stems extend 16″ to 40″ and are much branched. They are angled with ridges on the angles and are covered with long, soft, shaggy, spreading hairs. They are weak, reclining on the ground or climbing on adjacent vegetation.

The leaves are alternate, 2½″ to 6″ long, and pinnately divided into 5 to 12 pairs of leaflets. Each leaf has a tendril in place of a terminal leaflet and an even total number of leaflets. The tendril has 2 or 3 branches. The main axis of the leaf (rachis) is covered with long, soft, spreading hairs. There are a pair of conspicuous, lance-shaped, ¼″ to ½″ long, leaf-like appendages (stipules) at the base of each leaf stalk.

The leaflets are narrowly oblong to lance-shaped linear, short-stalked, ⅜″ to 13 ⁄16″ long, and ⅛″ to ¼″ wide. They are alternate to almost opposite. The leaf tips are angled or tapered to a short, sharp, abrupt point at the tip. The upper and lower surfaces are densely hairy. The margins are untoothed.

The inflorescence is a dense, spike-like, unbranched cluster (raceme) of 10 to 40 nodding flowers crowded on one side of the central axis. The raceme is on a long stalk rising from a leaf axil. The stalk is covered with long, soft, spreading hairs.

Each flower is ¾″ to 1″ long and is attached to the central axis by a short stalk (pedicel). There are 5 green to purple sepals (calyx) fused for most of their length into a bell-shaped, 1 ⁄16″ to ⅛″ long, hairy tube, then separated into 5 teeth. The lower 2 teeth of the calyx are much longer than the upper 3 teeth and are covered with very long, soft, shaggy hairs. The calyx is conspicuously swollen at the base and protrudes beyond the point at which the pedicel is attached. The appearance is of the pedicel attached to the side, not the end, of the calyx.

The 5 petals are variable in color, and can be bluish-violet, purple, or rarely white (f. albiflora). They form a butterfly-like corolla, typical of plants in the Pea family. They are organized into a banner petal at the top, two lateral wing petals, and between the wings two petals fused into a keel. The banner is notched at the tip and is usually darker in color than the remaining petals.

The fruit is a hairless, ¾″ to 13 ⁄16″ long pod containing 2 to 8 seeds.

American vetch (Vicia americana) stems are hairless. The leaflets hairless or sparsely hairy. The flower clusters are much smaller, with 2 to 9 flowers each.

Common vetch (Vicia sativa) leaflets are conspicuously squared off and indented at the tip. The flowers appear singly or in pairs on short stalks rising from the leaf axils.

Cow vetch (Vicia cracca ssp. cracca) foliage is hairless. The calyx is not swollen, and the pedicel appears to be attached to the end, not the side, of the calyx.