THE STRUCTURE OF GRASSES 5! 



are so considered. That is, in the description of the 

 grasses, what is really the fruit is referred to as the seed, 

 or in case of the large fruits, as the grain. 



In corn, wheat, rye, and some other grasses the seed 

 (fruit) separates from the chaff of the spikelet (the 

 glumes and lemmas), and, when threshed, comes into the 

 market as a naked grain or seed. In many others the 

 seed remains permanently enclosed in the lemma and 

 palea. To this group belong oats and barley. A grain 

 of oats or barley is, then, a covering of chaff, the lemma 

 and palea, with the real grain or seed inside. This grain 

 can be removed by cutting away the enclosing chaff. 



The commercial seed of bluegrass and redtop consists 

 of the broken up spikelets, each seed being enclosed by 

 the lemma and palea. In these and many other meadow 

 and pasture grasses the commercial seed is an uncertain 

 mixture of chaff and viable seed. The seed is so light 

 that in threshing and cleaning it is not separated from 

 the chaff, or at least very incompletely so. Furthermore 

 many of these grasses do not ripen all the seed of the 

 head at the same time, nor do all of the heads ripen, even 

 approximately, at the same time. Therefore when a field 

 is harvested, there is a comparatively small percentage of 

 ripe seed in the harvested heads. When these heads 

 are threshed, the resulting seed, as it is offered for sale, 

 consists of a rather small amount of ripe viable seed 

 mixed with a varying amount of chaff. Timothy is one 

 of the few meadow grasses in which the seed is little 

 diluted by chaff. The heads ripen about the same time 

 and the ripe seed can be rather easily separated from the 

 chaff. In sowing timothy one has a fairly accurate 

 5 



