DEPARTMENT REPORTS. 149 



The seeds are about the same length as red clover seeds, and a little 

 narrower, resembling a canoe in appearance, with both ends rounded. 

 They are brown in color and very shiny. It is very hard to separate 

 the seeds of this weed from those of red clover. There are several ma- 

 chines on the market for this purpose, but in most cases a considerable 

 portion of the red clover is sacrificed in the process of cleaning, S 173 

 W 196. 



Plantago rugelii — Rugel's or Black-seeded Plantain. Perennial, native 

 to this country. Seeds irregular in shape, flattened and black. Slightly 

 smaller than red clover seeds. Common in Michigan. S 175 W 197. 



Persicaria persicaria — Lady's thumb or Smartweed. Annual, intro- 

 duced from Europe. Slightly larger than red clover seeds. Seeds ovate, 

 somewhat heart-shaped, pointed at tip end, jet-black, shining. They are 

 usually elliptical in cross-section, but may be three angled. Rather 

 common, but not of itself a serious weed. It does more harm by harboring 

 insects which may do great injury to the crop. The plants should not 

 be allowed to seed. By cutting several times a season for two or three 

 years, it may be eradicated. .S 37 W 38. 



Rumex crispus — Curled, bitter or Yellow Dock. Perennial, introduced 

 from Europe. Seeds mostly sharply three-angled, reddish-brown, shin- 

 ing. Very common. All seed-bearing plants should be destroyed before 

 cutting the clover. They may be pulled up easily when the ground is soft 

 after a rain. Salt applied to the crown will destroy the root. S 11 W 41. 



Syntherisma spp. — Crab Grasses. Annuals, introduced from Europe. 

 Small crab grass seed is somewhat shorter than red clover, brown to black 

 in color after rubbing. The outer scale as long as the seed. S 11 W 21. 



Large crab grass is a little longer than red clover seed, and more 

 slender than the seed of the small crab grass. Light to darker green in 

 color. The outer scale only half as long as the seed. S 12 W 25. 



Some of the seeds found in red clover also occur in Alsike clover. 

 Among these maj^ be mentioned Pigeon Grass, Lamb's Quarters, Curled 

 Dock, Buckhorn, and Rugel's Plantain. Aside from these, tliere are 

 a few others which are ver^^ common, which do not occur in red clover 

 to any great extent. 



Cerastium vulgatum — Mouse-ear Chickweed. Annual or biennial. In- 

 troduced from Europe. Seeds ovoid to nearly circular, flattened, covered 

 wdth tubercles, light reddish-yellow to dark reddish-brown. Seeds very 

 small. Often found in lawns. May easily be screened out of alsike 

 clover. S 63 W 70. 



Lepidium spp. — Pepper grasses. Native, annual, and winter annual. 

 Seeds about half the size of red clover seeds. Somewhat egg-shaped, 

 reddish-yellow to reddish-brown. Flattened, with a groove down the 

 center. Mucilaginous when wet. Heavy seeder. S 92-95* W 100-101. 



Medicago lupulina — Black Medick or Yellow Trefoil. Annual, intro- 

 duced from Europe. Very common in Michigan. Used for forage in 

 Europe, but undesirable as a contaminant of other seeds. Seeds inclosed 

 in a black, oval, strongly veined pod. The seed is greenish yelloAV in color 

 and somewhat kidney-shaped, with a tubercle near the middle of the 

 concave side. Varies somewhat in size, but usually a little larger than 

 Alsike clover. Matures earlier than Alsike or red clover. S 108 W 119. 



*The illustrations Figs. 91 and 92 have boon interchanged. Fig. 92 belongs with the de- 

 scription for Apctalous Pcppergrass, and Fig. 91 belongs to the description of Field Pepper- 

 grass. 



