124 FODDER AND PASTURE PLANTS. 



YELLOW TREFOIL (Medicago hipuUna L.) 



Plate 22; Seed, Plate 27, Fig. 35. 



Other English name: Black Medick. 



Botanical description: Trefoil is closely related to the 

 Lucernes but is shorter lived. It is generally biennial but sometimes 

 lives only one year. It has a taproot with comparatively few 

 branches, about a foot deep on an average. The stems, which are 

 developed in great number from the crown of the root, are decumbent 

 or ascending. They often creep along the surface of the soil but 

 do not produce secondary roots. The plants are therefore spreading 

 in habit, especially as the stems are usually much branched. The 

 leaves consist of three leaflets, each of which has a short stalk. The 

 flowers are yellow, much smaller than those of the other species of 

 Medicago mentioned, and in a short cylindrical head. Trefoil closely 

 resembles certain yellow-flowered species of clover (Trifolium) but 

 can be readily distinguished from them. In true clovers the blossoms 

 do not fall off when flowering is over, but remain, withered, until 

 the fruit is ripe, making the heads brown and hiding the pods. In 

 Trefoil the blossoms fall off as soon as flowering is passed and the 

 pods are therefore visible while ripening. They are small, kidney- 

 shaped, rough-ridged and black — hence the name Black Medick. 

 Each pod contains only one seed and falls off without breaking. 



Geographical distribution: Trefoil is indigenous to all Europe 

 except its most northern parts, to northern Africa and to western 

 Asia. It is not a native of North America but is rather common 

 all over the continent, mostly growing like a weed. 



History: It has been cultivated in England for about one 

 hundred and fifty years. From the beginning of the nineteenth 

 century it began to be better known as a forage plant over central 

 Europe. It is not cultivated in Canada to any extent. In the 

 eastern provinces it is commonly found as an impurity in Red Clover 

 and Alsike and must then be considered a weed, as it is overripe when 

 the clovers are ready to cut. 



Cultural conditions: On account of its rather shallow root 

 system, Trefoil is more independent of the subsoil than the lucernes 

 and most clovers. It makes fairly good growth on rather poor land 

 but succeeds best on soils not too stifif and wet. Lime is necessary 

 for its proper development and a liberal amount of potash and 

 phosphoric acid are beneficial. 



