TAN 
THE NATURAL HISTORY OF BRITISH GRASSES. 31 
C.—Stamens, 3, STYLzs, 2. 
* Spikelets single flowered. 
+ Flowers spiked. 
. Leersia—glumes absent. 
. Alopecurus—spicate, glumes connected at the base, spike compact. 
. Phleum—spicate, glumes distinct, spike compact. 
. Ammophila—spicate, glumes pointed, with a tuft of hairs at the 
base, spike compact. 
. Lagurus—spicate, glumes with long bristly points, spike short and 
compact. 
. Phalaris—spicate, glumes broad, glistening seeds, smooth, spike less 
compact, 
10.—G@astridiwm—spicate, glumes swelling at the base, spike less com- 
pact. 
11.—Polypogon—spicate, outer glume awned, spike less compact. 
12. 
13, 
14. 
16. 
16. 
17. 
18, 
19. 
+t Flowers paniculate, more or less lax. 
Milium—panicle spreading, glumes herbaceous. 
Stipa—panicle erect, glumes coming out to a fine point, inner glumel 
with an awn ten times the length of the flower. 
Calamagrostis—panicle loose, glumes surrounded by silky hairs. 
Agrostis—panicle loose, glumes lancet-shaped, nearly equal. 
ttt Flowers spicate, arranged on two sides. 
Rottbolia—spikelets alternate, glumes equal. 
tttt Spikelets arranged unilaterally. 
Spartina—spikelets unilateral, glumes unequal. 
Cynodon—spikelets in alternate pairs on one side, glumes very un- 
equal. 
Digitaria—spikes branched, spikelets alternate on one side, glumes 
very unequal. 
Spikelets with one or two perfect florets, sometimes with one or addi- 
tional florets, which are imperfect. 
+t Fertile flowers, one ; imperfect flowers, one or two. 
. Setaria—panicle spicate, flowers surrounded by bristles. 
. Panicum—panicle spicate, spike-branched glumels, with short hairs. 
. Molinia—panicle contracted but not spicate, glumes acute, 
. Melica—panicle lax, glumes rounded. 
. Catabrosa—panicle spreading, glumes obtuse 
. Aira—panicle spreading, glumes unequal in size. 
. Triodia—panicle of few locustw, which are large and tumid. 
. Holeus—panicle lax, florets soft, with downy hairs. 
