| PLEUROPOGON GRAMINEZ 755 
POA 
simple racemes. Spikelets 5—20-flowered, all perfect or the up- 
per staminate. Two lower glumes empty, unequal, thin-mem- 
branous, 1-neryed, or the second imperfectly 3-nerved : flowering 
glumes’ longer, membranous, 7-nerved, the middle nerve excur- 
rent as a short point orawn. Palets nearly equalling the glumes, 
2-keeled, the keels winged or appendaged. Stamens 3. Styles 
short, with plumose stigmas. Grain free, enclosed in the glume 
and palet. | 
P. Californicum Benth. Vasey Grasses Pac. Slope, ii, 68.. Stems 
erect, or somewhat decumbent at base, rather weak, 2-4 feet high: sheaths 
smooth, equalling or exceeding the internodes, the lower ones short and 
membranous: ligules 2-3 lines long: leaves flat or folded, 3-21 inches.long, 
1-3 lines wide, obtuse, smooth, or barely rough above: : panicle a simple 
lecund raceme, 6-12 inches long: spikelets linear-oblong, 10-20-flowered, 
about 1 line long: empty glumes oblong, obliquely obtuse, smooth, 1-nerved 
below, the first 1-144 lines long, the second 1 line longer: flowering. glumes 
rance-oblong, erose or dentate at the membranous obtuse apex, scabrous, 
strongly 7-nerved, 3-4 lines long: awn arising below the apex,'1-5 lines 
long: palets oblong, obtuse, nearly equalling the glumes. In low meadow 
sands, southern Oregon to California. ', 
P. refractum Benth. Vasey 1. c. 69. Tufted from a strong creeping 
lootstock ; stems rather weak, 2-4 feet high, erect, smooth, simple: sheaths 
nearly smooth, equalling or slightly exceeding the long internodes: ligules 
+2 lines long, truncate: leaves flat. or folded, scabrous above, 2-10 inches 
long, 2-4 lines wide: panicle a simple secund raceme of 6-10. spikelets 
pendent on recurved pedicels, 6-12 lines long: spikelets linear-oblong, 
8-12-flowered, about 1 inch long: empty glumes lance-oblong, obtuse or 
emarginate, often denticulate, thin, smooth, 1-nerved, 2-3 lines long, the 
second slightly longer: flowering glumes lance-oblong, erose or dentate at 
the truncate membranous summit, nearly smooth, prominently 7-9-nerved, 
316-4 lines long: awn arising at the apex, 2-4 lines long: palet-linear, 
emarginate, shorter than the glumes. Along mountain streams, Oregon 
and Washington. . 
45 POA L. Sp. 67. 
Annual or perennial. grasses with flat or convolute leaves and 
numerous spikelets in open or contracted panicles. Spikelets 
2-6-flowered, compressed, the rachella usually. glabrous. . Flowers 
all perfect or rarely dicecious or polygamous. Glumes membran- 
ous, keeled, the two lower empty, 1-3-nerved: the flowering 
glumes longer than the empty ones, generally with a tuft.of cob- 
webby hairs at base, 5-nerved, the marginal nerves usually pu- 
bescent. Palets a little shorter’ than the glumes, 2-nerved or 
2-keeled. Stamens 3. Styles short, distinct, with plumose stig- 
mas. Grain free, or sometimes adherent to the palet. 
§ 2 Mericorpes. Glumes obtuse or barely acute. the empty 
ones: 1-5-nerved, the flowering ones without cobwebby hairs at 
base, not prominently keeled. | | 
P. argentea Howell Vasey Bull. Torr. Bot. Club. xv, 11. Stems 
slender, loosely tufted, 6-8 inches high, erect or somewhat decumbent at 
base: sheaths loose and membranous, longer than the internodes: ligules 
acute, 144-2 lines long: leaves of the sterile; shoots numerous, curved, 
