16 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 
coriaceous, much firmer than the lemma and palea, the palea some- 
times obsolete. 
Key to the genera of Nazieae. 
da. Spikelets single; first glume wanting___________________ 79. OSTERDAMIA. 
1b. Spikelets in clusters of 2 to 5; first glume present___________________ 2 
2a. Spikelets bearing hooked spines on the second glume, the group 
formingva little: burt 22 22 ue ee See eS 78. NAZIA. 
2b. Spikelets not bearing hooked spines, mostly cleft and awned____ 3 
3a. Groups of spikelets erect, the spike not one-sided_____ 80. Hrpartia. 
3b. Groups of spikelets nodding along one side of the delicate 
EUG 2 SN ES 2 A el al anplleaieianen chee nee 81. AEGOPOGON. 
TRIBE 7, CHLORIDEAE. 
Spikelets 1 to several flowered, in 2 rows on one side of a con- 
tinous rachis forming one-sided spikes or spikelike racemes, these 
solitary, digitate, or racemose along the main axis. 
A large and rather important tribe, confined mostly to warm 
regions. The group is heterogeneous, the only common character 
of the genera (aside from the characters that place them in Poatae) 
being the arrangement of the spikelets in one-sided spikes. Chloris 
and the allied genera form a coherent group, in which the spikelet 
consists of one perfect floret and, above this, one or more modified 
or rudimentary florets. Leptochloa, Eleusine, and their allies, with 
several-flowered spikelets, are more nearly related to certain genera 
of Festuceae. The spike is reduced to two or three spikelets or even 
to one spikelet and is sometimes deciduous from the main axis in 
Cathestecum and in some species of Bouteloua. In Campulosus 
there are two sterile florets below the perfect one. 
Key to the genera of Chlorideae. 
la. Plants monecious or dicecious; a low stoloniferous perennial_ 98. BULBIEIS. 
Ib. Plants, with, perfect) Howers 222 2s Bee eee eee 2 
2a. Spikelets with more than one perfect floret_____________________ 3 
8a. Inflorescence a few-flowered head or capitate panicle hidden 
among the sharp-pointed leaves; a low spreading an- 
WUT a a ee ear ela Ee 97. MUNROA. 
a) owed bavi(onrssieenieey: Gxdeenprele 4 
4a. Spikes solitary, the spikelets distant, appressed, sev- 
eral-flowered ct bates asta iva AY Ne 83. TRIPOGON. 
Ab. ‘Spikes more “hvac eee 5 
5a. Spikes numerous, slender, racemose on an elongate 
Fpl | eaperpetnie omen erat Pos AREY NSE seh pie ae! BUS 82. LEPTOCHLOA. 
5b. Spikes few, digitate or nearly so___..______________ 6. 
6a. Rachis of spike extending beyond the spike- 
Tet S222 eee ee ER Ure Oe 85. DACTYLOCTENIUM. 
6b. Rachis not prolonged_____-_--_-____-_-_ 84. ELEUSINE. 
2b. Spikelets with only 1 perfect floret, often with additional imper- 
fect florets; above. 0 23 So See De eae ee ee Se ee x 6 
