442 ALFALFA FARMING IN AMERICA. 
Examine Samples.—It is safe to get samples of 
alfalfa seed before buying and submit them to your 
experiment station for examination, or to the De- 
partment of Agriculture at Washington, choosing 
the seedsman according to the quality of his seeds. 
There are many honest seedsmen, but perhaps few 
competent or sufficiently careful seedsmen. 
Edgar Brown of the Bureau of Plant Industry 
Department of Agriculture, has made careful study 
of imported and home-grown alfalfa seeds and thus 
presents the case in Farmers’ Bulletin 194: 
Alfalfa seed is about the size of the seed of red clover, but is 
easily distinguished from it by its uniform light olive green 
color, as contrasted with the purple and yellow of clover seed. 
Unlike red clover, it varies considerably in shape. 
Adulteration.—Alfalfa seed is often adulterated; numerous sam- 
ples have recently been received at the seed laboratory for exam- 
ination which contain a considerable percentage of yellow trefoil 
seed. A few samples have also been received which contain burr 
clover. 
Yellow Trefoil—The seed which is most used in this country as 
an adulterant of alfalfa is yellow trefoil. It is darker green than 
alfalfa, so that a sample containing from 10 to 40 per cent of it 
looks brighter and better at the first glance than slightly discolored 
alfalfa seed. Yellow trefoil seed, however, can be easily dis- 
tinguished by an expert, on examination, through a small lens, 
by the differences in shape. Figure 2 shows the typical form of 
yellow trefoil seed. 
Yellow trefoil is a low-spreading, leguminous plant grown for 
sheep pasture on some of the poor, light soils of Europe where 
other forage crops do not grow. It is not grown to any extent 
in the United States and is of no value where clover or alfalfa 
is successful. 
Importation of Yellow Trefoil Seed—On account of the low 
price of yellow trefoil seed and its resemblance to alfalfa and red 
clover it is imported into this country in considerable quantities 
and used as an adulterant of both these seeds. During the six 
months from June 30 to December 31. 1903, 110,760 pounds of yel- 
