This section is from the book "Wayside And Woodland Blossoms", by Edward Step. Also available from Amazon: Wayside And Woodland Blossoms: A Guide To British Wild-Flowers.
Annual Meadow-Grass. Cock'sfoot-grass.
Poa annua. Dactylis glomerata.
- Gramineae. Most labiate flowers produce honey from the base of the ovary; and this, of course, is a distinct bribe to insects to visit them. It would not be an economical arrangement for a flower to provide honey for all comers without the plant getting a quid pro quo; we therefore find all sorts of "dodges" to ensure a service being done by the honey-seeker. As we have shown in the Bugle, the anther and stigma occupy the arch of the upper lip. As a rule the ripe anthers first occupy the foremost position, so that if a bee alights on the lower lip and pushes into the corolla for the honey his hairy back will brush off the pollen from the anthers. After the honey is shed the stigmas come forward and occupy the former position of the anthers. Should a bee that has got dusted with pollen at an earlier flower now pay a visit the stigmas will collect some pollen from his back and the ovules become fertilized. This is the general plan in the order Labiatas, but there are modifications in each genus.
In describing the Wall Barley we gave a general idea of the structure of grass flowers, and those of Poa are very similar to those of Hordeum; but the flower-cluster (inflorescence) is very different. In Hordeum (which see) this is a spike, bearing many three-flowered spikelets on each side. In Poa it is more branched and diffuse, and is called a panicle. In P. annua the branches grow two together, and are branched again. The spikelets are not awned as in Hordeum. There are eight British species of Poa, which, however, we have not space to describe. The name is Greek, and signifies fodder. All the species are perennial, with the exception of P. annua, which is an annual, as the name indicates. It flowers from April to September, and abounds in meadows, pastures and by roadsides.
The Cock's-foot-grass (Dactylis glomerata) is an ingredient of most pastures, and one of our most familiar grasses. Its long stout stem creeps for a distance, then rises very erectly and gives off horizontal flowering branches. The violet-tinted spikelets are gathered into dense one-sided clusters. Each spikelet contains three or four flowers, which are supposed to be arranged after the fashion of fingers on a hand, whence the Greek name Daktulos, fingers. Each flowering glume ends in a short awn-like point. This is the only British species. It is generally distributed, and will be found in waste places as well as pastures, flowering in June and July. The whole plant is rough to the touch. The leaves are long, flat and keeled.