LEGUMINOUS FORAGE CROPS 179 



201. Adulterations and Impurities. Alfalfa seed has been 

 extensively adulterated with black medic seed imported from 

 Europe. (236) Recently enacted laws will probably prevent 

 the practise hereafter. Sweet clover 



seed sometimes occurs, although rare- 

 ly as an adulteration. (250) Prob- 

 ably it more frequently occurs because 

 of the presence of this plant in alfalfa 

 fields. Seeds of the bur clovers have 

 been rather extensively used as an 

 adulterant in Europe, since these Alfalfa. Pod on the left, single 

 plants are widely distributed in South secd on ^At^s Enlarged 

 America, the hooked pods of which 



gather in the wool of sheep, the seed thus becoming a by- 

 product in the manufacture of woolen cloth. (238) The 

 most common impurities in alfalfa seeds as found in 53 samples 

 by the Nevada Station, 1 and in 15 samples by the Ohio Station, 2 

 are as follows: clover dodder (Cuscuta epithymum Murr.), 

 field dodder (C. arvcnsis Beyr.), lamb's quarters (Chenopodium 

 album L.), western atriplex (Atriplex truncata Torr.), prostrate 

 amaranth (Amaranthus blitoides S. Wats.), green foxtail grass 

 (Chaetochloa viridis (L.) Scribn.) and witch grass (Panicum 

 capillare L.). 



202. Dodder. By far the most serious impurity in alfalfa 

 seed is the dodder, of which there are now recognized to be 

 three species occurring on either red or mammoth clover or 

 alfalfa namely, field dodder (Cuscuta arvensis Beyr.), alfalfa 

 dodder (C. epithymum Murr.), and clover dodder (C. trifolii 

 Bab.). The first species is sometimes referred to as large seeded 

 dodder, while the last two species are not usually separated and 

 are commonly called clover or small seeded dodder. The species 

 most commonly occurring in commercial seed and upon alfalfa 



1 Nevada Sta. Bui. No. 47 (1900), p. 11. 



2 Ohio Sta. Bui. No. 142 (1903), p. 121. 



