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.
Nothing is known of the distribution of this plant except from its distribution to-day in the Northern Temperate Zone in Europe and North Africa. In Great Britain it is absent from Radnor, Carmarthen, Montgomery, Merioneth, Northumberland, Cheviotland, Renfrew, occurring in the East Lowlands only in Edinburgh, not in Kincardine or Aberdeen or Easterness in the E. Highlands, and elsewhere only in Dumbarton. From Moray and Dumbarton it ranges, however, to the extreme south elsewhere. It is very rare only in S.E. Ireland. It occurs in the Channel Islands.
Birds-foot is found on bare sandy or gravelly places, which may form parts of mountainous or hilly districts, or the lowlands, or parts of heaths or commons, where it is most frequent along the side of wide alluvial river valleys. But it may also be found on stony ground in wooded tracts, and also on walls and rocks generally.
The stems are numerous, prostrate, simple, downy, with leaves with lobes each side of a common stalk, the radical leaves prostrate, from 6-12, with a terminal larger leaflet.
The flowers are white with red veins, in a capitate head, on short flower-stalks, the calyx tubular, hairy, with 5 teeth. The pods are jointed, with curved valves, and the first name is given in allusion to the resemblance of the clustered pods to a bird's foot, hence the English and generic names.
Bird's-foot is at most about 3 in. high. Flowers may be seen in May up till August. The plant is perennial.
The type of flower is like the general Leguminous flower, but is very small, and the plant is prostrate, so that insect visits are restricted to smaller insects. The upper stamens are free. The stigma is pin-headed, with an inbent style, while the keel is very short, so that self-pollination is more frequent or possible. There is moreover no honey.
As in Lotus the pod, a schizocarp, breaks up into single joints of 1 cell each, and the seeds are thus dispersed separately around the plant, or blown by the wind when half-loose. They are also liable to be fractured by animals underfoot.
Photo. Dr. Somerviile Hastings - Bird's-foot (Ornithopus perpusillus, L.)
The Bird's-foot requires a sand soil, and is a sand-loving plant. It also favours barren and stony ground, and can be found on many of the older Precambrian, schistose, and granitic formations.
No fungi or insects infest this plant.
Ornithopus, Gesner, from the Greek ornis, bird, pous, foot, is so named from the similarity of the fruits to a bird's foot, and the second name refers to its diminutive character. The plant goes by two names, Bird's-foot, Fowl-foot.
Essential Specific Characters: 86. Ornithopus perpusillus, L. - Stem decumbent, spreading, leaves downy, pinnate, leaflets elliptic, in 5-12 pairs, flower white, veins crimson, with a small leaf at the base, pods jointed, curved, moniliform.