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 suiificient 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 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. 



