This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
This more or less local mural grass is found in the N. Temperate Zone in Europe, N. and W. Asia, and is possibly native in America, there being no trace of it in early plant beds. In Great Britain it does not grow in the Peninsular province in W. Cornwall, but throughout the Channel and Thames, Anglia, and Severn provinces, except in Stafford; in S. Wales, only in Carmarthen and Pembroke; in N. Wales, in Denbigh, Anglesea; in the Trent province; in the Mersey, not in Chester; throughout the Humber, Tyne, and Lakes provinces, except in the Isle of Man; and in the W. Lowlands, only in Renfrew and Lanark; in the E. Lowlands, only in Roxburgh, Berwick, Edinburgh; in the E. Highlands, in Fife and Forfar; in N. Highlands, in E. Ross. From Ross it ranges southward, but it is rare in Ireland and the Channel Islands.
The Flat-stalked Poa is not so common as some others, on account of its restricted habitat. It prefers a dry soil, and largely affects a mural habitat. Thus it grows commonly on walls with Vernal Grass, Mouse-ear Hawkweed, etc., and its natural habitat is a dry bank.
Slightly prostrate at the base, the stem is finally erect, oblique, flattened (hence the second Latin name), from a creeping rhizome which produces long soboles. The leaves are flat, rough or smooth. The upper leaf is longer than the sheath, with the upper knot near the middle of the stem. The ligule is short and blunt.
The flowers are in a secund (one-sided) branched panicle, which is narrowed. The spikelets have 5-7 flowers, and are oblong, egg-shaped, bluish-purple, with hyaline flowering glumes, with 3 hairy veins, and webbed, blunt, and smooth.
Flat-stalked Poa is 1-2 ft. high. The flowers are in bloom in June and July. The plant is perennial, propagated by division.
There are from two to many flowers in the spikelet. The lowest glumes are empty, the rest flowering. There are 3 stamens and 2 styles, which are short and terminal, and the stigmas are feathery. The flowers are anemo-philous.
This grass is a sand plant and addicted to a sand soil.
Poa, Theophrastus, is the Greek for grass, and the second Latin name refers to the contracted panicle. The plant is called Squitch Grass.
Essential Specific Characters: 338. Poa compressa, L. - Stem compressed, geniculate, leaves involute, panicle secund, ligule prominent, palea downy-veined.