Botanical description: Flat Pea is perennial with a vigorous root system consisting of a strong rootstock which sends out numerous side branches and secondary roots. The stems, which reach a height of from two to six feet, are decumbent or ascending, climbing and winding in all directions. They are much branched, angular, and provided with two broad wings. Each leaf consists of one pair of leaflets and a group of tendrils at the end of the elongated midrib of the leaf. The flowers are showy, dark rose-coloured and a trifle smaller than those of ordinary peas.
Geographical distribution: Flat Pea is indigenous to Europe. It grows naturally in woodlands, on stony hillsides, among shrubs, at the borders of woods, in thickets, etc.
Cultural conditions: It does not require particularly good soil but can be successfully grown on poor land. Sandy loam will produce the heaviest crop but good returns can be obtained from stiff clay or sand. As the roots go deep, the character of the subsoil is more important than that of the surface. A well drained subsoil is necessary for the proper development of the plant and stagnant water has always an injurious effect. The roots penetrate so far that the Flat Pea is very resistant to drought.
Agricultural value: The wild plant has a bitter taste and is not liked by stock. It is also claimed that it is apt to cause serious illness. The cultivated variety has no bitter taste; it is richer in nutritive constituents and its feeding value is much greater.
The agricultural value of Flat Pea is somewhat disputed. It is claimed that it is a valuable forage plant, especially when used as hay in mixtures, but the results obtained from experiments do not encourage its being grown on a large scale. It cannot be recommended for short rotations.
Fodder: When grown for hay it should be cut as soon as the flowers begin to appear or the stems begin to lodge. As growth starts early in spring and continues during the whole season, two or three cuttings can be taken from the second year on.
Seed growing: The best results are obtained on light, sandy soil, the crop reaching its full size during the third and fourth years. Harvesting is difficult because the pods ripen unevenly and break up in hot weather, scattering the seeds. They are generally hand picked as soon as they are ripe.
Quality of seed: The seeds are about the same size and shape as those of vetches, brown, their surface being finely roughened by a delicate net-like system of curved and branched veins.
Husbandry is an art so gentle, so humane, that mistresslike she makes all those who look on her or listen to her voice intelligent of herself at once. Many a lesson does she herself impart how best to try conclusions with her. See, for instance, how the vine, making a ladder of the nearest tree whereon to climb, informs us that it needs support. - Xenophon, The Economist, 434-355 B.C.
Methought I came to consider the wonderful actions which the Sovereign has commanded Nature to perform, and amongst other things I gazed upon the branches of the vines, peas and gourds which seemed to have some feeling and knowledge of their weakly nature; for being unable to support themselves, they threw out certain small arms, like threads, into the air, and finding some small branch or bough, proceeded to bind and attach themselves to it, without separating from it again, in order to support the parts of their weakly nature. - Bernard Palissy, Jardin Delectable, 1508-89.