H. 



seed only shows. The greater ragweed is like it but much lar- 

 ger. The seeds of Evening catchfly are kidney shaped about 

 1-18 of an inch in length, thickish and roughened, dull grayish 

 brown. This seed is very common in European and Eastern 

 grown clover seed. Several related forms have seed like it. The 

 Cow herb seed, however, is larger and more nearly spherical about 

 1-12 of an inch in diameter. Mature seeds jet black, imature 

 reddish, the surface is slightly roughened with minute project- 

 ing points. Another related seed is Corn cockle; these are about 

 1-10 of an inch in diameter, somewhat triangular in outline, 

 very rough; color, dull jet black. These seeds commonly occur 

 in wheat screenings. It is more or less poisonous. A number of 

 seeds in the mustard family are common among them; Field 

 mustard, Black mustard, the seeds of these are spherical about 

 1-18 of an inch in diameter, blackish, surface covered with a net 

 work of delicate ridges. The seeds have a sharp taste. The seeds 

 of Penny cress are somewhat egg shaped, broad in the middle, 

 brown, the surface has characteristic, 12-14 curved ridges, color 

 of seed reddish brown. The seeds of pepper grass of the same 

 family are small, about 1-16 of an inch in length, light reddish 

 yellow to brown, elongated, egg shaped, much flattened, the sur- 

 face is finely grooved, becomes mucilaginous when moistened. 

 The seeds are found in clover and in Iowa especially in timothy. 

 The "seeds" of Carrot are flattened, thin, about 1-8 of an inch 

 in length, bearing numerous spines, these are generally broken 

 off. Color of "seed' is whitish or yellowish. The seeds of Black 

 medick are similar to alfalfa, but more egg shaped than kidney 

 shaped, they are reddish or greenish with a smooth dull surface. 

 The pods are characteristic oval or kidney shaped, spirally coiled 

 and blackish. 



The White sweet clover seed is about 1-12 of an inch long, 

 somewhat flattened, resembling red clover in outline, elliptical- 

 oblong in outline, surface smooth and dull yellowish or green- 

 ish. The pods often occur in commercial seed, oval in outline 

 1-8 of an inch long, marked with prominent veins, and beaked. 

 The seeds of Common vetch are spherical blackish and large. 

 The seeds of Cinquefoil are about 1-24 of an inch in length, straw 

 colored with characteristic longitudinal ridges. 



Railways. The railways scatter many different kinds of weeds. 

 The right of way of the railway is usually one of the best col- 

 lecting grounds for the botanist. Such weeds as sunflower, Buf- 

 falo bur, Russian thistle, gum weed, spurge, western wheat grass 

 are common along the trunk lines. The seeds drop from passing 

 trains. 



Vehicles. It has often been observed that vehicles of various 



