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28. Poa L. 
Spikelets 2-o-flowered. Glumes 2, obtuse. 
Palets 2, both deciduous, lower carinate; upper 
2-carinate. Ovary sessile. 
1. P.pistans Grieseb. Lower palet round- 
ed; all leaves short and narrow, mostly convo- 
lute.—2¢. San Francisco. Summer. 
2. P. Catirornica Munro Ms. Dicecious; 
lower palet rounded; radical leaves half as 
long as the culm, mostly flat; culm-leaves short, 
frequently reduced to a mucro.—2f. San 
Francisco. Summer. 
3. P.TENUIFoLIA Nutt. Lower palet round- 
ed; radical leaves exceedingly narrow, mucro- 
nate; culm-leaves but little wider.—@. San 
Francisco. Spring. 
4. P. scapretta Gray. Dicecious; lower 
palet rounded. leaves carinate.—2. Oak- 
land. Summer. 
5. P. annua L. Lower palet acute; branches 
of the panicle single or in pairs; all leaves flat. 
©. Common. Spring. 
6. P. pratensis L. Florets %; lower palet 
acute; branches of the panicle mostly in fives; 
the entire plant smooth, only the margins of 
the leaves slightly scabrous.— 2f. Common. 
Summer. 
7. P. rrrviatis L. Florets 3: lower palet 
acute;. branches of the panicle mostly in fives; . 
the entire plant rough—2¢. Common. Summer. 
