This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
The Vetches are Leguminous plants, and the structure of the flowers is therefore very similar to those just described. The Vetches are chiefly climbing plants, and have pinnate leaves. The leaflets are numerous, and the leaf-stalk is continued for some distance beyond the leafy portion, where it becomes a clasping tendril, often divided into three or four branches. The Common Vetch is to be found in hedges and roadsides near cornfields, flowering from April to June. The flowers are pale purple in colour, and are produced singly or in pairs from the axils of the leaves. By some authorities this is not considered a true species, but merely a cultivated form of the Narrow-leaved Vetch (V. angustifolia). The seed-pods are slightly hairy, and from two to three inches in length. The name Vicia is the term by which the plants were known to the ancients and appears to have the same origin as Vinca (see page 5).
Vicia sativa. - LeguminoǼ. There are no less than ten British species of Vicia, but as some of these are very rare, we shall refer only to some of the commoner kinds.
I. Slender Tare (V. tetrasperma). Stem very slender, about 2 feet in height. Flowers singly or in pairs, pale blue. Pods with three or four seeds. Hedges and cornfields. May to August.
II. Common Tare (V. hirsuta). Similar to foregoing species, but hairy. Flowers smaller, pods shorter, hairy, and containing two seeds only. In similar situations. These are both annuals.
III. Tufted Vetch (V. cracca). With creeping rootstock and angled stem, climbing or spreading; somewhat silky. The bright blue flowers are borne in a dense one-sided raceme, to the number of twenty or thirty. The pod is beaked, about an inch in length, and contains a large number of seeds. Hedges and bushy places. June to August. Perennial.
IV. Bitter Vetch (V. orobtis). Leaves in seven to ten pairs of leaflets, without tendrils. Stem erect, branched, hairy. The flowers purplish-white, ten to twenty, in loose one-sided racemes. Pod pointed at each end, containing four or five seeds. Rocky and mountainous woods on the western side of Britain. May to September.
V. Wood Vetch (V. sylvatica). Perennial creeping rootstock. Stems, 3 to 6 feet, scrambling and trailing over bushes and undergrowth. Tendrils branched. Leaves beautifully divided into six or eight pairs of leaflets. Flowers white streaked and veined with purple, and borne loosely in a one-sided raceme, to the number of eight to eighteen. A beautiful species, found only locally in woods at high elevation.
VI. Bush Vetch (V. sepiuni). Creeping perennial rootstock, giving off runners. Leaflets, six to eight pairs. Flowers, dull purple, four to six in a cluster, not on a long stalk as in the Wood Vetch, but from the axils of the leaves, as in the Common Vetch. May to September. In hedges and bushy places.