186 A TEXT-BOOK OF GRASSES 
side, flattened on the other, straw-colored, red or brown, 
smooth, very minutely and rather faintly cross-wrinkled. 
Mi There are many varieties differing in the length and 
nie color of the bristles, in the color of the seed or fruit and 
ae in the size and lobing of the panicle or head. The name 
ate. Hungarian grass is given to the form with small purple 
g Bo heads. 
221. Pennisetum Pers—In this genus the 
spikelets, single or in groups, are surrounded by 
bristles as in Cenchrus but the bristles are 
distinct, and are often unequal in length or — 
plumose. The inflorescence is a spike or raceme. 
The most important species of the genus is the 
pearl millet, P. glaucum (L.) R. 
Br. (Fig. 26); P. americanum (L.) 
Schum.; Penicillaria spicata Willd. ; 
P. typhoideum Rich.). This is a tall 
coarse annual with 
¢ broad blades like sor- 
ghum and a close cylin- 
drical spike about a 
foot long and an inch 
or less in thickness. At 
_ maturity the smooth and shining ripened 
caryopsis bursts through the lemma and 
palea. Pearl millet is grown in Africa for 
food and to a limited extent in our southern 
states for forage. Two species of Pennise- 
f tum are commonly cultivated for orna- 
H ment, P. villosum R. Br., with short broad 
heads and long plumose bristles, and P. 
Fic. 26. Pen- Auppellii Steud., with more slender rose- 
nisetum glaucum. 
Inflorescence, x14. COlored spikes tapering at the apex. 
spikelet with invo- 
lucre of bristles, x5. (Penicillaria Willd.; Gymnothriz Beauv.) 
