354 Missouri Agricultural Report. 



Noxious Weed Seeds Found in Farm Seeds. 



The following brief descriptions point out the most conspicuous dis- 

 tinctions between the seeds of various noxious weeds. They only supple- 

 ment the illustrations to which they refer and which show the general 

 form and structure and the natural size of the seeds. The serial order is 

 employed for ready reference in the subsequent discussion of testing par- 

 ticular kinds of seeds. 



The seeds of sand bur (fig. 17, a) have somewhat the appearance of small 

 wheat kernels, usually light brown or straw-colored; common in alfalfa seed 

 from the Great Basin region. The spiny burs of this grass reduce the feeding 

 quality of alfalfa hay. 



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 greenish 

 or brown when in the chafif (as figured), the awn at the apex often broken 

 away, the club-shaped form of the rachilla segment distinguishing 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 resemble fescue and 

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

 greenish-colored; whole spikelets having the two empty scales noticeably joined 

 at the same level at the base of the spikelet (thus differing from most grass 

 spikelets) are invariably found with the individual seeds. Commonly found in 

 seeds of cereals and the coarse grasses, especially 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 



