246 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 
Penicillaria Willd., Enum. Pl. 2: 1036. 1809. A single species, P. spicatus, 
based on Holcus spicatus L., is described. 
Gymnothrix Beauv., Ess. Agrost. 59, pl. 13. f. 6. 1812. The type species is 
G. thourii, the one figured. Beauvois distinguished Gymnothrix from Pen- 
nisetum by the glabrous (not plumose) bristles. ; 
i The most important species of the genus is Pennisetum 
4, glaucum (L.) R. Br. (P. typhoideum Rich., P. ameri- 
canum (.) Schum., Penicillaria spicata (L.) Willd.), 
called in this country pearl millet (fig. 149). This isa 
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- 
ripe iy eogteasareurs 
Fig. 149.—Pearl millet, Pennisetum glaucum. Inflorescence, X 33; two views of spikelet 
and caryopsis, < 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. 
