Hayes and Garber - Cucurbit Breeding

208 BREEDING CROP PLANTS
sis), Canada bluegrass (Poa compressa), and redtop (Agrostis
palustris).
The variability (see Fig. 49) of each of the different species of
grasses presents a wealth of material for breeding purposes.
FIG. 49. Individual timothy plants grown under like conditions. The upper
plants are undesirable, one having weak stems and the other lacking vigor.
The lower plants are more desirable. They differ in density of plant and number
of culms. (Courtesy of Myers.}
Moreover, the fact that many of them may be conveniently propagated
as clones facilitates a study of the value of individual
FIG. 50. Flowers of timothy.
1. Spike.
2. Floret a, anther; b, filament; c, branched stigma; d, style; e, ovary;
/, outer glume.
3. Outer glume.
4. a, feathery stigma; 6, style; c, ovary.
5. Spikelet showing a, palea; 6, floral glume. (After Beat after Trinius and
Scribner.)
Size: 1, %n; 2, 80n; 3, 4, 5, greatly enlarged.