Testing Farm Seeds. 359 



hard, the name "stoneseed" is often applied to them; found in seed of red and 

 crimson clovers, alfalfa, cereals, grasses, etc. 



Rat-tail plantain seeds (fig. i8, 1) are small, flat, angular and black; the 

 scar in the center of one side; common in seed of clovers and some grasses. 

 Known also as broad-leaved plantain and as Rugel's plantain; a persistent 

 weed. 



Buckhorn seeds (fig. i8, m) are smooth, shining, rounded on one side with 

 a deep groove on the other, brown or amber colored, becoming coated with 

 mucilage when placed in water"; one of the commonest impurities of farm 

 seeds, often very abundant in seed imported from Europe. Not abundant in 

 alfalfa seed produced in the Western States. Known also as plantain, English 

 or narrow-leaved plantain, and rib-grass. 



Ragweed seeds (fig. i8, n), as they commonly occur, are somewhat top 

 shaped, usually with a crown of several teeth or spines; the outer covering is 

 often broken away, the seed then appearing pear-shaped, smooth and brown; 

 common in American red clover and in cereal grain. 



Gumweed seeds (fig. i8, o) are whitish or straw-colored, variable in form, 

 sometimes wrinkled; found chiefly in alfalfa seed from the Western States. 



Wild sunflower seeds (fig. i8, p) have the form and the striped, mottled 

 appearance familiar in the cultivated sunflower seeds, but are much smaller; 

 common in alfalfa seed and other seeds from the Western States. 



Oxeye daisy seeds (fig. i8, q) are very small, but are readily distinguished 

 by the lo slender, white ridges which extend from end to end, one end usually 

 bearing a knob-like projection; found frequently, but usually not abundant, in 

 clover seed and small grass seed. 



Canada thistle seeds (fig. i8, r) are smooth, light brown, straight or curved, 

 having a cup-like rim at one end, a projecting point often within the rim; found 

 in clover seed, particularly alsike from Canada; sometimes in seed of clover and 

 grasses, from Europe. 



Bull thistle seeds (fig. i8, s)-are larger than those of the Canada thistle, 

 light colored, striped lengthwise with brown, the rim at one end often yellow- 

 ish; common in red clover, alfalfa and grass seeds. 



Wild chicory seeds (fig. i8, t) are brown or straw-colored, usually mottled, 

 the crown scales at the broader end sometimes rubbed away; common in im- 

 ported clover, alfalfa, and certain kinds of grass seeds, occurring in lesser de- 

 gree in American-grown seed. 



Other Weed Seeds Commonly Found in Farm Seeds. 



Certain kinds of weed seeds other than those termed noxious under 

 the preceding heading are found frequently, sometimes abundant, in 

 various kinds of farm seeds, and thus cause inquiiy from one examining 

 seeds. The degree of noxiousness of this class of weed seeds difEers with 

 the kinds and with the conditions of locality, climate, etc., under which 

 they are sown. While some of the kinds included in the present list are 

 looked upon, at least locally, as pests, many of the kinds mentioned are 

 of little importance as field weeds. Since it is essential to distinguish 

 the relatively unimportant from the important seeds, a fairly accurate 



a See "An Improved Method of Separating Buckhorn from Red Clover and Alfalfa 

 Seeds," Circular 2, Bureau of Plant Industry, U. S. Dept. of Agriculture, 1908. 



