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 hedges, roadsides, waysides, where it is an escape from cultivation. The habit is as in the last, climbing or trailing. The stem is stout. The leaflets are in 5-7 pairs, variable, elliptic, inversely heart-shaped, or egg-shaped to oblong, blunt or notched, the lower shorter and broader, the upper narrow, linear, blunt, short-pointed. The stipules are half spear-shaped, entire. The flowers are axillary, solitary, or usually paired, nearly stalkless, pale-purple, the standard smooth. The calyx-teeth are equal, lance-shaped to awl-like, as long as their tube. The pods are mostly parallel to the stem, stalkless, 2-3 in., linear, 4-10-seeded, rather hairy or silky. The seeds are rounded, slightly flattened at the border. The hile is linear, extending \ round the seed. The plant is 6-18 in. high, flowering from May to July, and is a herbaceous annual.
The habitat of this species is bushy places on a gravelly soil, and waste places. The habit is trailing or climbing. The stems are numerous from the root, hairless except above, wavy. The leaves are long. The tendrils are long, branched. The leaflets are in 1-2 pairs above, linear, lance-shaped, blunt, short-pointed, acute. The stipules are large, toothed, half arrow-shaped. The flowers are pale-purple with paler wings. The calyx-teeth are slender, longer than their tube, unequal, lance-shaped, awl-like. The calyx is swollen below. The stalks are 1-3-flowered, less than the leaves, the ultimate ones as long as the calyx. The pod is shortly stalked, netted, hairy, linear-oblong, rough, large, beaked, 4-6-seeded. The seeds are large, round, speckled, dark-brown, with an oval hile. The style is hairy all over above. The plant is 1-2 ft. high, flowering from May to August, and is a herbaceous perennial.
The habitat of this species is grassy bushy places, banks. The plant has the grass habit. The stems are ascending, very slender. There are no leaves or tendrils, but grass-like leaf-stalks which are leaflike, or phyllodes, which serve as leaves. They are long, flat, entire, fine-pointed, with many parallel nerves. The stipules are minute, awl-like. The flowers are erect, crimson or purple, the stalks 1-2-flowered, long, slender. The teeth of the calyx are lance-shaped, the lower longest. The pods are slender, cylindrical, flattened at the border, hairless. The seeds are granulate, round, with a small, oval hile. The plant is 1-3 ft. high, flowering in May and June, and is a herbaceous annual or perennial.