POACEAE 
Inflorescence a short congested raceme: leaf-blades 
with thick conspicuous cartilaginous margins. 
Inflorescence a contracted or open panicle: leaf-blades 
not cartilaginous on the margins. 
Inflorescence composed of long branches along which the 
appressed spikelets are arranged on short pedicels, or 
sometimes only a one-sided raceme. 
Lateral nerves of the flowering scale glabrous. 
eke of the flowering scales copiously pubescent with long 
airs. 
Panicle contracted : flowering scales broadly oval, rounded 
98. 
97. 
at the apex. 102. 
Panicle pon and diffuse: flowering scales lanceolate and 
acute. 
Callus of the flowering scales glabrous. 
Second empty scale similar to the first. 
Rachilla of the spikelet continuous: palets often per- 
sistent. 1 
Rachilla of the spikelet articulated. 
Spikelets very small and numerous, less than 3 mm. 
long, usually several-many-flowered. 103. 
105. 
Spikelets large, about 6 mm. long, 2-3-flowered. 
Second empty scale very dissimilar to the first, broad and 
rounded at the summit. 
Flowering scale coriaceous in fruit: seed beaked and exserted from 
the scale. 1 
Flowering scales 5-many-nerved. 
Spikelets with two or more of the upper scales empty, broad and 
enfolding each other. 1 
Spikelets with the upper scales flower-bearing, or smaller and 
101. 
ERIONEURON. 
TRIDENS. 
DIPLACHNE. 
RHOMBOLYTRUM. 
00. REDFIELDIA. 
03. ERAGROSTIS. 
ERAGROSTIS. 
KOELERIA. 
04. EATONIA. 
07. KORYCARPUS. 
06. MELICA. 
empty. 
Empty basal scales 3-6. 108. UNIOLA. 
Empty basal scales 2. 
Spikelets dioecious. 109. DISTICHLIS. 
Spikelets perfect : 
Bornein fascicles which are arranged in a glomerate or in- 
terrupted panicle. 11 
Borne in panicles or racemes, but not in fascicles. 
Stigmas inserted at or near the apex of the ovary. 
0. DACTYLIS. 
Flowering scales with the nerves parallel. 112. PANICULARIA. 
Flowering scales with the lateral nerves converging 
above toward the midnerve. 
Flowering scales strongly keeled on the back, pu- 
bescent on some or all of the nerves: hilum 
punctiform. 111. Poa. 
Flowering scales rounded on the back, at least 
; below: hilum linear. 113. FESTUCA. 
: Stigmas plainly inserted below the apex of the ovary. 114. BROMUS. 
TRIBE XII. HORDEAE. 
Spikelets singly arranged at the rachis nodes. 
Spikelets with the flowering scales with their backs to the rachis ; empty 
scale 1. 115. LoLium. 
Spikelets with the flowering scales with their sides to the rachis: empty 
Scales 2, 116. AGROPYRON. 
Spikelets 2-6 at each rachis node: 
1-flowered. 117. HoRDEUM. 
2-many-flowered. 
Empty scales usually as long as the flowering ones. à c 
chis of the spike articulated, its internodes readily separating at 
the joints: empty scales 2-many-parted or cleft. 1 
18. SITANION. 
Rachis of the spike continuous: empty scales entire. 119. ELYMUS. 
Empty scales wanting or minute. 120. HysTRIX. 
TRIBE XIII. BAMBUSEAE. 
Shrubs or trees with the leaf-blades usually articulated with the sheaths. 121. ARUNDINARIA. 
1. TRIPSACUM L. 
Tall perennial monoecious grasses, with stout rootstocks, usually broad flat leaf-blades 
and spicate inflorescence. Spikes articulated, elongated. Staminate spikelets 2-flowered, 
in pairs at each joint of the upper portion of the axis, of 4 scales, the outer 2 empty, 
coriaceous and shining, the inner 2 thinner, each enclosing a hyaline palet and a flower 
consisting of 3 stamens.  Pistillate spikelets 1-flowered, in excavations in the lower inter- 
nodes of the rachis, the outer scale very hard, thick and shining, concealing the more deli- 
cate remaining scales, the fourth scale enclosing a flower with a slender style. Stigmas 2, 
exserted. Grain enclosed in the appressed outer scale and the internode. 
Spikes in pai ingle, terminal and axillary: leaf-blades 1-2 em. 
p x ; irs or more, rarely single, termina y a 
Spike single, terminal, none axillary : leaf-blades 8 mm. broad or less. Der, Suid. 
