HITCHCOCK—MEXICAN GRASSES. 
Spikelets 1 to many-flowered, the imperfect or rudi- 
mentary floret, if any, uppermost (except in 
Phalarideae); rachilla articulated above the 
persistent glumes (except in Oryzeae, Cinna, 
Polypogon, Sphenopholis, and Spartina); spike- 
lets usually laterally compressed. 
Culms woody; blades often with a short petiole 
articulated with the sheath. (BamMBUSEAE.) 
Stamens 3. 
Spikelets 1-flowered............---.--+--++-+- 
Spikelets 2 to many-flowered. 
Glumes 1 or 2; sterile lemmas none; spike- 
lets loose, many-flowered, elongated, 
paniculate or racemose. ........------- 
Glumes 2; sterile lemmas 1 or 2; spikelets in 
racemes or one-sided spikes, these ar- 
ranged in tufts at the culm nodes...... 
Culms herbaceous. 
Spikelets in two close rows, sessile or nearly so, 
forming a one-sided spike (in Bulbilis only 
the staminate so). (CHLORIDEAE.) 
Spikelets monecious or dicecious, the two sexes 
very unlike. 
Pistillate inflorescence capitate; 
spikelets 2 or 3-flowered........- 
Pistillate inflorescence a loose spike; 
nate spikelets 1-flowered. 
First glume of pistillate spikelet very 
small; lemma of fertile floret with 3 
long aWNS.........------+----------- 
First glume of pistillate spikelet some- 
what shorter than the second; lemma 
of fertile floret 3-toothed.......-..... 
Spikelets all alike, bearing perfect florets and 
often more or less rudimentary ones above. 
Spikelets with 2 or more perfect florets. 
Spikes digitately arranged. 
Rachis extended bey ond the spikelets 
as a point... eel eee ee ee eee eee 
Rachis not extended ce ceeeeee cece eeeeee 
Spikes solitary or racemosely arranged. 
Inflorescence a single spike-like raceme. 
Inflorescence of several racemose spikes 
or spike-like racemes. 
Racemes spikelet-bearing from the 
base; lemmas glabrous or only 
slightly pubescent............-.. 
Racemes naked below; lemmas vil- 
lous on the nerves or callus. ..... 
Spikelets with one perfect floret. 
Spikelets bearing no sterile lemmas above 
the perfect floret, awnless. 
staminate 
stami- 
133. 
96. 
97. 
98. 
93. 
92. 
91. 
94. 
95. 
189 
BamBos (p. 387). 
. CHUSQUEA (p. 387). 
. ARUNDINARIA (p. 386). 
. ARTHROSTYLIDIUM (p. 387). 
BuLBILs (p. 352). 
Opizia (p. 353). 
PRINGLEOCHLOA (p. 353). 
DacTryLoOcTENtum (p. 347). 
ELEvuSINE (p. 346). 
TRIPOGON (p. 346). 
LEPTOCHLOA (p. 348). 
GouInNIA (p. 351). 
