8 



KEY TO THE GENERA. 



Primary Series A. PANICACEiE. — Spikelets articulate on the pedicels 

 below the glumes. Spikelet with one fertile flower, the male or barren flower, 

 if any, below it. 



Tribe I. — Paniceje. — Pertile spikelets with one terminal bisexual or 

 female flower, with or without a male one below it. Glumes four or three, 

 the upper flowering one of a firmer texture, the outer one usually smaller, 

 sometimes wanting. A palea to each flower. Stamens three, rarely fewer. 

 Grain enclosed in the hardened (rarely thin, but stiffened) upper glume and 

 palea. Awns rare, and when present neither twisted nor bent back. 



Series i. Spikelets bisexual. 



Infloresence not braeteate. No bristle-like involucre. 

 Fruiting glume hardened. 

 Spikelets with three glumes. 



Pedicels not callous at the summit. Flower - 



ing glume not awned ... ... ... 1. Paspalum. 



Pedicels with a callous annulus or cup at 

 the summit. Flowering glume with a 

 point or short awn ... ... ... 2. Eriochloa. . 



Spikelets with four glumes. 



Outer glume shorter than the others, often 



minute, not awned ... ... ... 3. Panicum. 



Outer glume with a long awn ... ... 4. Oplismenus. 



Spikelets surrounded by or intermixed with abortive 

 branches of the panicle, forming a lobed or 

 bristly involucre. Pruiting glume hardened. 

 Spikelets intermixed with long persistent bristle- 

 like branches, and falling off from them ... 5. Setaria. 



Involucres crowded or distant along a simple 

 rhachis, each enclosing one to three 

 spikelets, and falling off with them. 



Involucres of numerous simple or plumose 

 bristles completely surrounding the 

 spikelet ... ... ... ... ... 7. Pennisetum. 



Involucre of several outer bristles and inner 

 flat lobes completely surrounding one 

 to three spikelets and at length hardened 8. Cenchrus. 



Branches of the particle produced beyond the base of 

 the last spikelet. Pruiting glume stiff, but 

 scarious and rather thin. 

 Spikelets solitary, or few along the slender in- 

 articulate branches of the panicle ... 9. Chamseraphis. 



Series ii. Spikelets unisexual. 



Stems prostrate. Spikelets dioecious, in dense heads 13. Spinifex. 



Tribe II — Andropogone^:. — Pertile spikelets with one terminal bisexual 

 or female flower, with or without a male one below it. Glumes four or 

 rarely fewer, one of the outer ones the largest enclosing the fruit, the third 

 smaller, thin and hyaline, sometimes wanting, the upper or flowering one 



