ELEVENTH ANNUAL YEAR BOOK— PART XI 729 



The seeds of wild oats (fig. 17, b) are similar to seeds of cultivated 

 oats, but always have a twisted and bent, brown or straw-colored awn 

 (sometimes broken away) from near the middle, a tuft of light-brown 

 hairs on the rachilla segment and about the characteristic, cup-shaped 

 rim of the scar at the base of the seed; widely distributed and common 

 in seeds of cereals (especially oats) and large-seeded grasses. 



Chess (or cheat) seeds (fig. 17, c) are straw colored, sometimes green- 

 ish or brown when in the chaff (as figured), the awn at the apex often 

 broken away, the club-shaped form of the rachilla segment distinguish- 

 ing this from cultivated grass seeds; common in seeds of cereals and 

 large-seeded grasses generally; the reddish-brown, trough-shaped free 

 grains sometimes appear in clover seed. 



Darnel seeds (fig. 17, d) are robust, straw colored, and in the absence 

 of the slender awn somewhat resemble large seeds of meadow fescue and 

 English rye-grass; common in seed of cereals, particularly wheat. 



Quack (or couch) grass seeds (fig. 17, e) closely resembles fescue and 

 rye-grass seeds, but they are usually slenderer, light (or yellowish), some- 

 times greenish colored; whole spikelets having the two empty scales no- 

 ticeably joined at the same level at the base of the spikelet (thus differ- 

 ing from most grass spikelets) are invariably found with the individual 

 seeds. Commonly found in seeds of cereals and the coarse grasses, espec- 

 ially in the seed of awnless brome-grass imported from Europe. 



Dock seeds (fig. 17, f) are sharply 3-angled, reddish brown, smooth, and 

 shining; one of the commonest of the weed seeds of farm seeds generally, 

 the reddish brown ripened flowers (shown at the right of the figure) 

 commonly appearing in seeds of cereals and coarse grasses. Several 

 kinds of dock seeds occur in farm seeds, the commonest being that of 

 curled dock (figured). The similar seeds of broad-leaved (or bitter) 

 dock are sometimes found. Another kind having smaller seeds which are 

 rounded instead of pointed at the base occurs in Chilean red clover seed. 



Black bindweed seeds (fig. 17, g) are coarse, 3-angled, black when the 

 outer covering is removed; the outer straw-colored, greenish, or brown 

 covering (flower scales) may be present or partly or wholly broken away; 

 common in all kinds of coarse farm seeds from all sources, particularly 

 in seed of cereals, millet, and flax. 



Russian thistle seeds (fig. 17, h) occur both with and without the 

 gray or light brown hull (flower scales) ; the seeds proper have a thin 

 coat covering the slender spirally coiled, greenish embryo; common in 

 alfalfa seed from the Western States and in flaxseed; doubtless occasion- 

 ally introduced in seed from Russia. As an impurity of alfalfa seed it 

 strongly suggests Western States production. 



The seeds of corn cockle (fig. 17, i) are black or brown, angular, and 

 covered with fine spiny tubercles; common in seed of cereals, millets, 

 vetches, and flax from all sources. 



White campion seeds (fig. 17, j) are mostly light gray, the surface 

 finely tubercled, the light color distinguishing this kind from the next 

 two; common in imported crimson clover and grass seeds; sometimes 

 found in red clover seed. 



