ELEVENTH ANNUAL YEAR BOOK— PART XI 725 



casual examination is usually given seed by purchasers makes adultera- 

 tion, substitution, and misbranding possible. 



The remedy lies in familiarity with the distinguishing characters of 

 individual seeds. By comparing seeds of the several kinds with the il- 

 lustrations and descriptions here given one should be able to distinguish 

 them individually without much difficulty. 



Leguminous Seeds — All the true clovers (as red, alsike, white, and 

 crimson), alfalfa, the vetches, trefoil, sweet clover, and bur clover, pro- 

 duce seeds in a pod which (except in trefoil, sweet clover and bur clover) 

 opens at maturity. In red clover, trefoil, and sweet clover a single seed 

 is produced in each pod. Consequently, the seeds of each kind are very 

 similar in form. Alfalfa and bur clover produce several seeds in a spiral 

 pod, resulting in considerable variation in the form and size of individual 

 seeds. Seeds of the true clovers, alfalfa, trefoil, bur clovers, and sweet 

 clover are more or less flattened and (excepting crimson clover) are 

 notched in the edge. Within this notch the seed scar, or point of attach- 

 ment to the plant, appears as a small, but distinct ring. In the more or 

 less spherical seeds of the vetches the scar is an oval, wedge-shaped, or 

 slender spot on the curved surface. In this class of seeds the scar is an 

 important mark of distinction. In several of the small-seeded kinds of 

 leguminous plants occasional pods appear even in well-cleaned lots of 

 seed. 



Most of the grass seeds, also oats and barley, appear "in the chaff," 

 that is. the grains or kernels of the seed illustrated by the kernels of 

 wheat and the hulled seeds of timothy are usually covered by the dried 

 chaffy flower scales. The difference in size, form, and structure of this 

 chaff marks the different kinds of grass seeds. 



Seeds of the grasses — Grass seeds are produced in clusters (spikelets.) 

 Some clusters contain several seeds arranged along a common axis 



(rachilla). At maturity the 

 clusters break apart, each 

 seed carrying a piece of the 

 cluster axis (rachilla seg- 

 ment). Such seeds have two 

 \\f~'^ chaff scales, one (the lemma) 

 larger than the other (the 

 palet or palea) . Examples of 

 ", / .. ' -v v this class of grass seeds are 



•**#■ '%.;/' found in orchard grass, mea- 



■* \\ a "' i b v e dow fescue, rye-grass, brome- 



Fig. 16.— A spikelet and florets ("seeds") grass, and in the blue-grasses, 

 of Kentucky bluegrass; a. Spikelet as it T nnn thpr class of era«sps 

 appears at maturity; b, the same having- ln anotner Class or grasses 

 the florets spread apart, showing- the each cluster contains but a 

 jointed rachilla; o, back view of a floret, . . 



showing the lemma (1); d, front view of single seed which, therefore, 

 the floret, showing the edges of the lem- y, a „ nf . rflr v,illa spempnt The 

 ma (1), the palet (2), and the ranchilla nas D0 iacmlla segment. 1 ne 

 segment (3); e, the grain or kernel of seeds of broom-corn (or 



grain) millet are a good ex- 

 ample of this class, the seed scales, lemma, and palea being hard, 



\ 1 



