246 BULLETIN 772, T7. S. DEPARTMENT OF AGRICULTURE. 
Penicillaria Willd., Enuin. PI. 2: 1036. 
based on Hole us s pi cat us L., is described. 
Gymnothrix Beauv., Ess. Agrost. 59, pi 
G. thourii, 
nisetuni by 
1S09. A single species, P. spina t us. 
13. f. 6. 1812. The type species is 
the one figured. Beauvois distinguished Gymnothrix from Pen- 
the glabrous (not plumose) bristles. 
The most important species of the genus is Pennisetum 
glaucum (L.) E. Br. (P. typhoideum Rich., P. ameri- 
canum (L.) Schum., Penicillaria sulcata (L.) Willd.), 
called in this country pearl millet (fig. 149). This is a 
robust annual. 4 to 8 feet tall, with broad blades like 
those of corn or sorghum, and a dense, erect, cylindric 
spikelike panicle as much as a foot long, the stem woolly 
below the spike, the involucre containing usually two 
spikelets about as long as the bristles. Pearl millet dif- 
fers from the other Paniceae in having an enlarged cary- 
opsis bursting through its lemma and palea. The cary- 
opsis, or "seed," is deciduous by an articulation above 
the fertile lemma, the bristles and the floral bracts re- 
maining on the spike. Pearl millet is widely cultivated 
in tropical Africa and Asia, the seed being used for hu- 
man food. The species has been cultivated since pre- 
Fig. 149. — Pearl millet, Pennisetum glaucum. Inflorescence, X 1 ; two views of spikelet 
and caryopsis, X 10. 
historic times, its wild prototype being unknown. In the United 
States pearl millet is used to a limited extent in the Southern States 
for forage, especially for soiling. 
