PANICEZ 177 
sisting of the chartaceous fertile lemma and palea inclos- 
ing a caryopsis the covering of which is thin. The genus 
Amphicarpon is peculiar in having 2 kinds of spikelets, 
ordinary spikelets in a terminal panicle, and underground 
cleistogamous spikelets borne on short subterranean 
branches that appear like rhizomes. Only the latter bear 
seed. 
Kery To THE GENERA OF PANICEZ 
A. Spikelets not all alike. 
B. Spikelets all perfect, but those of the aérial 
panicle not perfecting grains; the fruitful 
spikelets cleistogamous, borne on_ sub- 
terranean branches. Florida to New Jersey. AMPHICARPON. 
BB. Spikelets not all perfect, the inflorescence 
bearing pistillate spikelets above and 
staminate spikelets below; panicles ter- 
minating the branches; blades _ broad, 
elliptical. Florida 
AA. Spikelets all alike. 
B. Spikelets sunken in the cavities of the 
PARMENE COPY ARIS So cca oe ae ok Dek STENOTAPHRUM 
BB. Spikelets not sunken in the rachis. (Par. 223). 
c. Spikelets subtended or surrounded by 1 to 
many bristles (sterile branchlets), these 
distinct or more or less connate, forming 
an involucre. 
D. Bristles persistent, spikelets deciduous..CHa#TOCHLOA 
DD. Bristles falling with the spikelets at (Par. 220). 
maturity. 
E. Bristles not united at base, usually 
slender, often plumose............ PENNISETUM 
EE. Bristles more or less united into a bur- (Par. 221). 
feke? AEN, 8 Es SSE wa, CENCHRUS 
cc. Spikelets not subtended by bristles. (Par. 222). 
D. Fruit cartilaginous-indurated, not rigid, 
papillose, usually dark-colored, the 
lemma with more or less prominent 
white hyaline margins not inrolled. 
E. Fruiting lemma _ boat-shaped, the 
hyaline margins narrow. Florida 
Sa MRIMANEE o's she kA ee ries ia ANTH/NANTIA 
EE. Fruiting lemma convex, the hyaline 
margins broad. 
F. Fruit lanceolate-acuminate; second 
glume and sterile lemma long- 
silky. Florida to Arizona........ VALOTA. 
