AGRICULTURAL SPECIES OF BENT GRASSES. 19 
to contain, can not at present be identified with certainty or dis- 
tinguished by the seed alone from American-grown Rhode Island 
bent seed and colonial bent seed. Finally, the seed of carpet bent 
or strictly stoloniferous forms of bent can not be recognized at present. 
These phases of the subject are open to further investigation. 
The commercial kind of seed is often suggested and sometimes 
determined by evidence of its source of production which appears in 
the associated weed seeds and other seeds found in the sample. 
Though certain kinds of weed seeds are found in both domestic and 
imported seed, others are strongly suggestive either of domestic or 
of foreign production. In this matter, the absence of certain kinds of 
seeds is as helpful as the presence of others. 
= 
THE SEEDS DESCRIBED. 
The following descriptions of the seeds of redtop, Rhode Island 
bent, and velvet bent are based chiefly upon their appearance under a 
low-power compound microscope. When the distinguishing charac- 
ters are recognized by this means the use of a high-power hand lens 
enables one to recognize with a considerable degree of accuracy 
the kinds in bulk quantity or in mixtures. A complete qualitative 
and quantitative analysis requires the use of a compound microscope 
and of laboratory methods. 
SEED OF REDTOP (AGROSTIS PALUSTRIS HUDS.; AGROSTIS ALBA L. OF MOST BOTA NISTS). 
Lemma 0.05 to 0.08 of an inch in length, lanceolate to lanceolate- 
oblong in outline, somewhat glisten- 
ing, the longest lemmas exceeding-the 
grain about one-third their length, 
the upper third or half of the lemma 
translucent and silvery white, the 
lower part opaque and often straw 
colored, the apex usually distinctly 
three angled, occasionally four an- 
-gled by the absence of the keel vein; 
the surface glabrous, very finely 
and longitudinally striate; the awn 
oe mendaty straights eT gunn aural diet ta seods dsb, ad 
not spirally twisted, rarely exceed- c the palet is not wrinkled and covers the 
ing the apex of the lemma or bent grain. Inseedsdand ¢ the palet is wrinkled 
5 sues and shorter than the darker grain, (The 
and twisted, arismg near the apex natural size is shown at f.) 
of the lemma, rarely as low as the 
middle of the latter, often a mere projection from the surface (fig. 
3, 4); hairs at the callus present or wanting; palet exhibiting two 
types in appearance: (1) Not wrinkled, scarcely translucent, evi- 
dently striate, usually equaling or exceeding the grain (fig. 3, 2); 
(2) wrinkled, often shorter than the grain and between two-thirds 
