KIDNEY VETCH. I25
Climate: Although the roots are not very deep, Trefoil will endure a certain amount of drought without serious injury. It is only fairly resistant to cold weather. It prefers a medium warm climate and makes a splendid growth where moisture is abundant in the air and the soil.
Agricultural value: On account of its biennial or even annual character, Trefoil is most suitable for short rotations. Its decumbent branches and spreading habit make it of little value for hay as much of the plant escapes the mower. Its chief value is for pasture. It starts earlier than most pasture plants, grows up quickly, and produces quite a valuable green fodder. It stands close cropping remarkably well and for this reason is good for sheep.
Its feeding value and yielding power being not comparable to those of Alfalfa or Red Clover, it should not be grown where these plants succeed. It should not be used alone for pastures and only to a limited extent in mixtures; too large a proportion is apt to prove detrimental to the other constituents. Although rather short-lived, it produces abundant seed and may consequently choke out other pasture plants. Twenty pounds of good seed are sufficient to cover an acre.
Seed: The seed of Trefoil is relatively cheap and it is therefore sometimes used to adulterate Red Clover. It is often found in commercial samples of Red Clover, Alsike or Alfalfa. Its colour is like that of Alfalfa seed, with which it is sometimes confused. Black kledick seeds are thicker and shorter, being egg-shaped while Alfalfa seed is kidney-shaped or sometimes irregularly angled.
The seed weighs sixty pounds per bushel.
KIDNEY VETCH (Anthyllis Vulneraria L.) Seed, Plate 27, Fig. 36.
Botanical description: Kidney Vetch is perennial with a short-branched rootstock from which numerous overground stems arise, from one-half to one foot high. The leaves are numerous, consisting of a number of leaflets in pairs and an odd one much larger than the others. The flowers are in dense heads which are generally in pairs. They are commonly yellow but sometimes white or red. It is a honey plant frequently visited by insects which carry pollen from one flower to another. But if the plants are isolated, so as to make visits by insects impossible, the flowers are automatic-ally fertilized by their own pollen.