This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The habitat of this plant is chalky and gravelly places, dry, sunny pastures. The habit is prostrate, or ascending. The stem is short, clothed with soft hairs, which are black above, slender. The rootstock is slender, branching, straggly. The leaves are shorter than the stout flower-stalks. The leaflets are in 8-10 pairs, blunt, small, numerous, oblong, linear. The stipules are united below opposite the leaves. The flowers are purple, in large heads, or ascending, egg-shaped racemes. The calyx has black hairs longer than the bracts. The pods are shortly-stalked, hairy, short, egg-shaped, nearly erect, included in the calyx, 2-seeded. The ovary is twice as long as the stalk. The plant is 2-9 in. high, flowering from June to August, and is a herbaceous perennial.
The habitat of this plant is dry and sandy places. The habit is prostrate or ascending. The stem is threadlike, and the plant is nearly hairless, bluish-green. The leaves have lobes each side of a common stalk (hence pinnatus), stalked. The leaflets are distant, oblong, elliptic, the lowest pair distant from the stem. There are no bracts (hence ebracteatus).
The flowers are small, bright-yellow, in heads, 2-5, the standard red outside, with red veins. The flower-stalks are as long as the leaves. The pod is slender, beaked, or curved upwards; the 10-14 joints cylindrical, rough or granulate. The plant is 4-18 in. high, and flowers from May to August. It is a herbaceous annual.
The habitat of this Vetch is dry places, banks, etc. The habit is climbing, as in V. sa-tiva. The plant is stout, the stem slender. The upper leaves have linear, lancc-shaped, oblong leaflets, acute or blunt. The lower leaflets are notched or inversely heart-shaped, or egg-shaped. The flowers are smaller, often solitary, or in pairs, rose colour. The calyx-teeth are nearly as long as the tube. The pods are chiefly spreading, not splitting the calyx. The plant is 6-12 in. high, flowering from April to July, and is a herbaceous annual.
The habitat of this Vetch is dry gravelly and sandy places, dry pastures, roadsides. The habit is prostrate, then ascending. The plant is hairy. The stem is slender, spreading. The leaflets are in 1-3 pairs acute, blunt, or notched, inversely egg-shaped, linear to oblong. There are no tendrils or simple ones. The flowers are small, solitary, stalkless, lilac-purple, in the axils. The calyx is funnel-shaped, and the calyx-teeth are awl-like, equal, straight, as long as the tube. The pods are hairless, linear, stalkless, tapered both ends, beaked. The 8-12 seeds are tubercled, obtusely angled, nearly cubical, with a very short hilum. The plant is 3-8 in. high, flowering in May and June, and is a herbaceous annual.