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 cultivated ground, railway banks, hedges, and fields, hedgebanks and borders of fields, and it is frequently sown by farmers. The plant has an erect habit. The stem is erect, hollow, branched. The leaves are divided into three. The leaflets are inversely egg-shaped, oblong, toothed, notched above, with a short abrupt point. The flowers are yellow, blue, or purple, in a raceme of many flowers, the flower-stalks not so long as the calyx, the main stalk longer than the leaves. The pods are flattened in a loose spiral of 2-3 turns, downy, the hairs close. The plant is 1-2 ft. in height. It flowers from May to August, and is a herbaceous perennial.
The habitat of this plant is cultivated fields, clover fields, etc. The plant has an erect habit, with slender stems, and is downy or softly hairy with spreading hairs, the leaves shortly stalked, the leaflets inversely egg-shaped or heart-shaped. The stipules are egg-shaped, blunt, and hairy. The flowers are in a long, cylindrical, later egg-shaped head, crimson, terminal, on stalks, the calyx teeth not so long as the corolla, 10-veined, and hairy, spreading in fruit, and the mouth is also hairy. The petals do not fall. The wing is longer than the keel, the latter springing back into position after it is depressed by insects, and the stamens are exposed. The stamens are dia-delphous. The filaments have swollen tips. The style is thread-like. The pod is stalkless, 1-seeded. The plant is 6-18 in. in height, and flowers in June and July, being a herbaceous annual.
The habitat of this plant is cornfields, waste places, gravel pits, and about hedges and roadsides. The habit is climbing, the stem weak. The leaves are tendrils, and the stipules, which are large, egg-shaped, spear-shaped, nerved, do the work of the leaves. The first and second leaves in the seedling are scale-like and 3-lobed, with awl-like points, the third and fourth compound, with one pair of leaflets and stipules, and an awl-like tendril. The fifth and later leaves are awl-like points and stipules. The point becomes a tendril above. The flowers are pale yellow, single, rarely on long stalks, erect. The lobes of the calyx are green, linear, about as long as the corolla. The pod is sickle-shaped, broad, nearly erect, beaked, netted, and the 6-8 seeds are smooth and flattened. The plant is 1-3 ft. in height, and flowers in June and July, being a herbaceous perennial.
This plant is a denizen, found in cornfields. The plant is of climbing or trailing habit. The rootstock is creeping, the rootlets tuberous. The stem is angled, not winged. The leaflets (one part) are inversely egg-shaped, with spreading nerves. The leaf-stalk and tendrils are stout, the stipules are large and half-arrowshaped. The flowers are borne on long flower-stalks, 2-5, crimson, in a raceme. The bracts are awl-like. The ultimate flower-stalks are longer than the calyx, the latter with teeth, triangular. The pod is smooth, netted, the seeds smooth and round. The plant is 2-4 ft. in height. It flowers from June to August, and is a herbaceous perennial.