Poa. | LXXXIX. GRAMINEA., 539 
Spikelets about 3- or 4-flowered. Flowering glumes 
strongly nerved 5. P. procumbens. 
Spikelets 6- or more flowered. Flowering glumes faintly 
nerved 6. P. rigida. 
Panicle reduced to a single spike, with the lower spikelets ocen- 
sionally clustered. Root annual 7. P. loliacea. 
Panicle scarcely 1-sided, the branches and pedicels slender. 
Flowering glumes all keeled, with minute silky hairs on 
the keel or sides. 
Root annual. No hairs on the axis of the spikelet F 8. P. annua. 
Stock perennial. Minute woolly hairs on the axis under the 
flowering glumes. 
Panicle ovate ov oblong, more or less crowded. 
Stem creeping at the base. Leaf-stalks much flattened . 9. P. compressa. 
Stock tufted. Stems and lower sheaths thickened at the 
‘base. 
Stems bulbous at the base. Panicle contracted . . 15. P. bulbosa. 
Stems scarcely bulbous. Panicle rather loose. : . 14. P. alpina. 
Panicle loose or very long. 
Glumes pointed. Flowers about 3. 
Panicle long. Spikelets oblong or lanceolate. 
Stems weak. Leaves narrow and flaccid. Panicle 
slender : : ; j : 5 ; ; . 12. P. nemoralis. 
Stems tall. Leaves long and stiff. Panicle very long 
and rather stiff . : . Molinia cerulea. 
Panicle very spreading, with slender branches, and few, 
rather large, ovate spikelets. (Alpine plant.) . . 13: P. lana. 
Flowering glumes rather obtuse. Panicle spreading, with 
numerous spikelets. 
Rootstock with creeping scions. Flowers about 4 in the 
spikelet. Lateral nerves of the flowering glumes 
very faint. : : : ‘ . : ‘ . 10. P. pratensis. 
No creeping scions. Flowers 2 or rarely 3 in the spike- 
let. Lateral nerves of the flowering glumes con- 
spicuous ’ bode j : é : ‘ . 11. P. trivialis. 
1. P. aquatica, Linn. (fig. 1236). Reed P.—A stout, reed-like per- 
ennial, 4 to 6 feet high, with a creeping rootstock. Leaves flat and 
very rough on the edges. Panicle much branched, spreading, nearly 
a foot long. Spikelets numerous, with 5 to 8 or 10 flowers. Outer 
elumes unequal, thin, and l-nerved. Flowering glumes about 14 lines 
long, loosely imbricated, strongly 5- or 7-ribbed, rather obtuse, and 
scarious at the top. Glyceria aquatica, Sm. 
In wet ditches, and shallow waters, throughout Europe and temperate 
Asia, except the extreme north, and in North America. Frequent in 
England and Ireland, rarer in Scotland. Fl. summer. 
2. P. fluitans, Scop. (fig. 1237). Floating P.—An aquatic perennial, 
often 2 or 3 feet high or more, with rather thick but weak stems, creep- 
ing at the base; the leaves often floating on the surface of the water. 
Panicle erect and slender, a foot long or more; the branches few and 
usually erect. Spikelets few, 4 to 1 inch long, with from about 8 to 
near 20 flowers. Outer glumes unequal, thin, and l-nerved. .Flower- 
ing glumes loosely imbricated, 14 to near 3 lines long, strongly 5- or 
7-ribbed, scarious at the top, obtuse or slightly pointed. Glyceria 
Jluitans, Br. 
In wet ditches, and stagnant or slow-running waters, throughout 
Europe and Russian Asia, except the extreme north, and in North 
America. Common in Britain. fv. all summer. [G. plicata, Fries., is 
a variety with flowering glumes, twice as long as broad, and divaricate 
fruiting spikelets. ] 
