62 



FLORA. 



Flowering scale and palet membranous ; second scale spiny (in ours). 



III. Zoysieae. 

 Flowering scale and palet of the perfect flower coriaceous or chartaceous ; spikelets 



involucrate in Nos. 18 and 19 ; scales 3 or 4. IV. Paniceae. 



Spikelets flattened laterally, i-flowered ; scales 2. V. Oryzeae. 



B. Spikelets i -many-flowered ; rachilla generally articulated above the two lower 

 scales (below them in Nos. 38, 46, 54 and 61) and frequently extending beyond the flower 

 in i-flowered spikelets. 

 Culms herbaceous. 



Spikelets upon pedicels in panicles, spike-like panicles or racemes, not in rows. 

 Spikelets with but i perfect flower, which is terminal except in Nos. 42 



and 43. 

 Fifth scale enclosing a perfect flower ; palet i-nerved. 



VI. Phalarideae, 

 Third scale enclosing a perfect flower ; palet 2-nerved. 



VII. Agrostideae. 



Spikelets with 2 or more perfect flowers (or one staminate in Nos. 46 and 51). 

 Flowering scales generally shorter than the empty lower ones, usually 



with a bent awn on the back. VIII. Aveneae, 



Flowering scales generally longer than the empty lower ones, unawned 



or with a straight awn from the apex. X. Festuceae. 



Spikelets in two rows, forming a one-sided spike or raceme. 



IX. Chlorideae. 

 Spikelets in two opposite rows, forming an equilateral spike (unilateral in 



Nardus). XI. Hordeae. 



Culms woody, at least at the base ; tall reeds. XII. Bambtiseae. 



Tribe I. MAYDEAE. 



Fertile spikelets imbedded in the joints of the thick rachis. I. Tripsacum. 



Tribe II. ANDROPOGONEAE. 



Joints of the rachis not much thickened nor excavated for the reception of the spikelets. 

 Spikelets alike, perfect. 2. Erianthus. 



Spikelets not alike, the sessile perfect, the pedicelled staminate, empty or wanting. 

 Inflorescence composed of spike-like silky racemes. 



Racemes usually in pairs, rarely in 3's~5's and digitate, the rachis internodes 

 and pedicels opaque ; fourth scale of the spikelet with a blade. 



4. Andropogon. 



Racemes panicled, the rachis internodes and pedicels thickened on the mar- 

 gins and with the intervening portion thin and translucent ; fourth scale 

 of the spikelet pedicel-like, without a blade. 5. Amphilophis. 



Inflorescence paniculate. 



Pedicelled spikelet wanting (in our species). 6. Sorghastrnm. 



Pedicelled spikelet present and usually staminate. 7. Sorghum, 



Joints of the rachis greatly thickened and excavated for the reception of the spikelets. 



3. Manisuris. 



Tribe III. ZOYSIEAE. 



Spikelets in a terminal spike ; second scale spiny. 8. Nazia. 



Tribe IV. PANICEAE. 



Spikelets without a subtending involucre of bristles or valves. 

 Spikelets all alike. 



Second scale of the spikelet not enlarged nor saccate at the base. 

 Spikelets arranged in one-sided racemes. 



Spikelets with a swollen ring-like callus at the base. 



12. Eriochloa. 

 Spikelets without a callus. 



Racemes alternate or scattered, rarely in a terminal pair, or some- 

 times single and slender, in the latter case the spikelets 

 broadly oval and obtuse. 

 Spikelet of 3 scales. 



