VETCHES AND VETCH-LIKE PLANTS 489 



Serradella is a much-branched, slender-stemmed plant 

 with pinnate leaves, a stout tap root, umbeled rose- 

 colored flowers, and pods which break into joints, these 

 constituting the commercial seed. Each joint is reticu- 

 lated on the outside, but about one-fifth of these are 

 empty. Well-grown plants of serradella reach a height 

 of 2 feet. 



Serradella is adapted primarily to moist sandy soils 

 and a cool growing season. Unlike its effect on many 

 other legumes, lime is not helpful but often deleterious 

 to its growth. The young plants will withstand several 

 degrees of frost in the spring, but not so much when in 

 bloom. 



In Europe serradella is sown in early spring, either alone 

 on fall-sown rye or with spring-sown oats, using 40 to 60 

 pounds of seed to an acre. The seedlings grow very slowly 

 at first, except the root. If sown alone, it may be cut for 

 green feed by July. The first cutting of hay is made when 

 the blooming has nearly ceased, and a second cutting can 

 be made in the fall. The hay must be cured with great 

 care, as the leaflets fall off easily. The average yield of 

 hay in Germany is said by Werner to be 2500 to 5000 

 pounds to an acre. 



Seed is harvested from the second cutting, and the 

 yields are said to range from 350 to 1200 pounds to 

 an acre. 



Serradella may be found to be useful on moist sandy 

 lands in the northernmost states and in Canada, and per- 

 haps as a fall-sown crop in the extreme south. Many of 

 the failures with this plant have doubtless been due to 

 lack of inoculation. 



597. Square-pod pea (Lotus tetragonolobus) is native 

 to the countries bordering on the Mediterranean, where 



