KIDNEY VETCH. 125 
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 pro- 
duces quite a valuable green fodder. It stands close cropping re- 
markably 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 Medick 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 isa 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. 
