a 
AGRICULTURAL SPECIES OF BENT GRASSES. 
17 
DISTINGUISHING THE SEEDS. 
In consequence of the close relationship existing between redtop 
_and the other bent grasses, their seeds are very similar in appearance 
and are readily mistaken, one kind for another, unless they are 
examined critically with the aid of a low-power compound microscope 
or a high-power 
hand lens. 
The distinguish- 
ing characters of 
the minute seeds of 
redtop and other 
bent grasses which 
are of practical 
value in recogniz- 
ing the species are 
found in the seeds 
when freed from 
the outer envelop- 
ing chaff (fig. 3). 
matured seeds. 
each other and to the inclosed seed. 
Fic. 3.—Hulled seeds of redtop (Agrostis palustris), enlarged, illustrating 
the general structure of seeds of bent grasses: 1, Back of the lemma; 
a, the keel vein; 6b, the marginal veins; c, the callus. 2 and 3, The 
opposite side of the seed; d, the palet, not wrinkled and covering the 
grain; e, the palet, wrinkled and shorter than the grain. 
lemma haying an awn (fj) and intermediate veins (gq). 
4, Back of a 
This chaff (fig. 4) readily separates from well- 
In immature seeds the chaffy scales tend to cling to 
An unnecessary proportion of 
chaff usually constitutes a considerable part of the bulk of Rhode 
Fic. 4.—Chaff, or hull, of redtop seed: a, Whole 
spikelets usually devoid of seed in ‘“‘chaffy”’ 
grades; 6, separated scales of the same; @ and b 
represent the outer chaff oftheseed. (Enlarged.) 
Island bent, colonial bent, and 
South German mixed bent seed. 
Domestic redtop is sold with the 
chaff present as “‘chaffy”’ redtop 
and free of the chaff as “fancy,” 
“hulled,” or “recleaned”’ redtop. 
An opinion on the kind of seed 
found in a given sample and its 
probable source is based upon (1) 
the structural characters of the 
seed, which show its kind, and (2) 
theimpuritiesfound in the sample, 
such as other grass seeds, weed 
seeds, and chaff, which usually 
indicate the source of production. 
GENERAL STRUCTURE. 
Freed from the two outer chaffy scales, called the glumes, an indi- 
vidual seed of redtop or of the other bent grasses consists of a grain 
lying between two unequal, more or less inclosing scales (fig. 3, 
1 and 2). 
is termed the lemma. 
The larger scale, which exceeds the length of the grain, 
The smaller is termed the palet or palea. 
The palet is especially important in distinguishing the kind of seed. 
While the palet varies somewhat in the same kind of seed, it differs 
