90 



Lucerne and Trefoil Seed. 



[may, 



valuable for alternate husbandry, is also useful in small propor- 

 tion in permanent mixtures, as upon congenial soils it propa- 

 gates itself by seed in an unobtrusive way so as to become 

 practically permanent. Though not standing up well to the 

 scythe, trefoil is a palatable addition to the first, and perhaps 

 second, year's crop, at the same time helping to form a compact 

 bottom. 



The seeds of trefoil are smaller than lucerne, having a smooth, 

 shiny surface, and in fresh new seed are greenish-yellow in colour. 

 The projecting tip of the radicle so characteristic of this species 



Fig. 6. — Bokhara Cloa'er Seed {Melilotus alba) (magnified six diameters). 



enables one to recognise it readily. The plumpness, good colour, 

 and brightness of the seed, or the reverse of these desirable fea- 

 tures, are useful guides as to the quality of any sample, and old 

 seed is quickly detected by the lack of lustre and its dull brown 

 appearance. 



Trefoil, on account of its low price, is never adulterated ; 

 being cheap it rather offers an inducement to the unscrupulous 

 vendor to use it as an adulterant in higher-priced clovers. 



The impurities most met with in samples of trefoil are the 

 oval, oblong, brownish seeds of Plantago lanceolata (rib grass), 

 easily determined by one surface being convex and shiny, and 

 the other side concave. There are also found the ripened half- 



