Poa. | LXXXIX. GRAMINE. 539 
often germinate, flower, ripen and shed its seeds, and die away, in the 
course of a few weeks. 
9. P. compressa, Linn. (fig. 1240). Wlattened Poa.—A perennial, 
seldom above a foot high, with a creeping rootstock, and erect stems 
more or less flattened at the base. Leaves rather short, with flattened 
sheaths, and a short, obtuse ligula. Panicle oblong, 2 to 3 inches long, 
slightly spreading, but rather crowded, with many of the spikelets sessile, 
and the branches turned towards one side, but not so much as in P. pro- 
cumbens and P. maritima. Spikelets ovate-oblong, usually 4- to 6-flowered, 
with occasionally a few woolly hairs on the axis. Flowering glumes 
about a line long, with minute silky hairs on the keel; the lateral nerves 
not prominent, 
On dry, barren, waste ground, and frequently on walls, in temperate and 
southern Europe, in Russian Asia, and North America, extending far 
into Scandinavia, but not an Arctic plant. Frequent in England and 
Scotland, but less so further north, and rare in Ireland. 7. all summer. 
10. Ps pratensis, Linn. (fig. 1241).. Meadow Poa.—A perennial, 1 
to 2 feet high, with a more or less creeping rootstock or emitting creeping 
scions aboveground. Leaves rather narrow, with a short, obtuse ligula. 
Panicle 2 to 3 inches long, with slender, spreading branches. Spikelets 
numerous, ovate or oblong, all or nearly all stalked, each with about 4 
flowers. Flowering glumes rather more than a line long, with minute 
silky hairs on the keel; the lateral nerves scarcely prominent. 
In meadows and pastures, throughout Europe and central and Russian 
Asia, from the Mediterranean to the Arctic Circle, in North America, and 
reappearing in the southern hemisphere. Abundant in Britain. 7. 
summer, commencing early. 
11. ®. trivialis, Linn. (fig. 1242). Roughish Poa.—Very near 
P. pratensis, but there are no creeping scions; the stems are usually 
taller and more slender; the ligula of the leaf longer; the panicle more 
slender, often 6 inches long, with slender, spreading branches; the 
spikelets have seldom more than 3 flowers, and usually only 2. Flowering 
_ glumes as in P. pratensis, except that the lateral nerves are much more 
conspicuous. | 
In meadows and pastures, with the same geographical range as P. pra- 
tensis, and at least as common. Abundant also in Britain. 7. summer, 
commencing early. 
12, P.nemoralis, Linn, (fig. 1243). Wood Poa.—A perennial, 1 to 
2 feet high, tufted, or slightly creeping at the base, erect, but weaker 
and more slender than the last two species, with narrower leaves, their 
ligules very short. Panicle contracted or spreading, with slender branches. 
Spikelets compressed, lanceolate or ovate, with 2 to 5 flowers in each, 
and scarcely any woolly hairs on the axis, Flowering glumes rather 
more than a line long, lanceolate, more pointed than in the last two 
species, with a line of small silky hairs on each side and another on the 
keel. P. Parnellit, Bab., and P. Balfourti, Parn. 
In woods and shady places, and on moist mountain rocks, throughout 
Europe and Russian Asia from the Mediterranean to the Arctic regions. 
Frequent in Britain. £7. summer, A mountain variety, often distinguished 
under the name of P. cesia, Sm., has the stems usually shorter, the panicle 
