216 PRACTICAL BOTANY. 



001. Spikelets each subtended by an involucre of several 

 or few awned pedicels. Spiked panicle dense (an apparent 

 cylindric spike). Setaria. 



Gr. VII. 60. 



W. II. 20. 



No involucre of awned pedicels. Lower glume 

 usually shorter, sometimes minute, rarely wanting. Pales 

 3 or 4. Stigmas usually purple. Spikelets either 2 or 3 to- 

 gether, or imbricated, or scattered. Spikes often 1 -sided, 

 panicled, racemed, or sometimes almost digitate. 



Fauicum (618). 



Gr. YII. 59. 



W. II. 18. 



00^. Spikes lateral or terminal, commonly clustered or 

 digitate, hairy, mostly silky. Spikelets in pairs, not in 

 threes, the peduncled sterile one usually neutral, often a mere 

 pedicel, and only in one species, A./urcatus, Muhl, staminate. 



Andropogon. 

 Gr. VIII. 64. 

 W. V. 69. 



Panicle narrowly oblong, clothed with fawn-color- 

 ed hairs, at length drooping. Spikelets in pairs or threes, 

 the one or two, stalked sterile reduced to hairy pedicels. 



Sorghum nutans, Gray. 

 {Aiidro2)ogon nutans^ L.) 

 Gr. VIII. Qo. 

 W. 69. 



003. (565.) Spikelets (3- to Y-flowered) disposed in 2-4 

 (rarely more) 1-sided, digitate spikes. Lower pale keeled. 



604. 



Spikelets disposed in solitary spikes, racemes, or 

 panicles 605 



004. Upper glume awn-pointed. Lower pale boat- 

 shaped, pointed. Spikelets 3-tlowered, the upper flower ste- 

 rile. Spikes usually 4 ; rhachis mucronate at the naked tip. 



Dactyloctenium iEgyptiacum, Willd. 

 Gr. IIL 21. 

 W. 59. 

 Upper glume larger than the lower, both obtuse. 



