186 



A TEXT-BOOK OF GRASSES 



Pen- 



glaucum. 



Fig. 26, 

 nisetum 



Inflorescence, XJ4. 

 spikelet with invo- 

 lucre of bristles, X5. 



side, flattened on the other, straw-colored, red or brown, 

 smooth, very minutely and rather faintly cross-wrinkled. 

 There are many varieties differing in the length and 

 color of the bristles, in the color of the seed or fruit and 

 in the size and lobing of the panicle or head. The name 

 Hungarian grass is given to the form with small purple 

 heads. 



221. Peimisetum 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. typhoidciim 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 growai in Africa for 

 food and to a limited extent in our southern 

 states for forage. Two species of Pennise- 

 tum are commonly cultivated for orna- 

 ment, P. villosum R. Br., with short broad 

 heads and long plumose bristles, and P. 

 RuppelUi Steud., with more slender rose- 

 colored spikes tapering at the apex. 

 (Penicillaria Willd.; Gymnothrix Beauv.) 



