The “web" looks like hyphæ of a mould.
Caryopsis ellipsoid-acute, with traces of the stigma. It falls easily. No distinct groove, section somewhat triangular. Rachilla truncate.
| Fig. 54. Poa nemoralis. c, the minute “seed" (to the right) and caryopsis (to the left) nat. size. a, the "seed," × 8; b, the caryopsis, × 8. Traces of a basal “web," not shown here, occasionally occur. Nobbe. | Fig. 55. Poa pratensis. Type of a “webbed seed." a, “seed," × about 7; b, caryopsis (inverted), × 7. Between are the same, nat. size. Note the nerves on the palea and the conspicuous "web" at the base a. Nobbe. | Fig. 56. Poa trivialis. a, “seed," nat. size and × 8; b, caryopsis, nat. size and × 7. Note the conspicuous "web." Nobbe. Cf. Fig. [43]. |
Poa compressa, L.
Palea obtuse, nearly glabrous and nerveless, or faintly 3-5 nerved and with a faint web. It is close to P. pratensis.
Poa trivialis, L. (Fig. [56]).
"Seed" 2-2·5 mm., and with a bluish or bronzed cast. Caryopsis 1-1·5 mm.
Palea acute, distinctly five-ribbed, glabrous, the margin scarcely overlapping. Caryopsis grooved, blunt and more tightly held in the palea.
P. trivialis differs from P. pratensis chiefly in the distinct ribs and smoother palea, grooved caryopsis, and bluer hue.