40 PANICACEiE. 



The grasses of this polymorphous genus number about 130 

 species, are generally branching, often found in poor land, and 

 vary much in habit. They are widely dispersed in the warmer 

 portions of Europe, Asia, Australia and America, 



Bentham reduces the species of Andropogon proper to 5 sec- 

 tions. 



I have followed E. Hackel, who places our species of the genus 

 under subgenera as follows : 



Subgenus 1. Schizachyrium (Nees as a genus). Spikes slen- 

 der, single, terminal or axillary, the thickened joints of the rachis 

 with a cup or toothlike appendage at the apex, pedicellate spike- 

 lets usually neuter, about as long as the sessile ones, second glume 

 of the sessile spikelets awnless or with a very short awn, floral 

 glume often cleft nearly to the base, bearing an awn between the 

 lobes ; culms usually low and slender. 



a. Spikelets and pedicels clothed with soft hairs . . . .(b) 



b. Hairs reaching beyond the spikelets 1 



b. Hairs not reaching beyond the spikelets 2 



a. Spikelets and pedicels containing a few short hairs in rows 



or lines (c) 



c. Annual, culms filiform, bearing spikes at all the nodes, 



blades 2-6 cm. long 3 



c. Perennial, culms stouter, leaves longer . . . .(d) 



d. Lateral spikes all exserted (e) 



e. Lateral spikes very few (f) 



f. Spikelets 5-6 mm. long 4 



f. Spikelets 7 mm. long 5 



e. Lateral spikes numerous 6 



d. Lateral spikes partly embedded (g) 



g. Sessile spikelets about 4 mm. long . . 7 

 g. Sessile spikelets about 6 mm. long . . 8 

 g. Sessile spikelets about 7 mm. long . . 9 

 Subgenus 2. Diectomis (Beauv. as a genus). Pedicellate spike- 

 lets laterally compressed, neuter, broad, twice as long as the sessile 



ones, second glume of sessile spikelets awned 10 



Subgenus 3. Artiikolophis. Spikes mostly in pairs, rarely 

 digitate or panicled, terminal or axillary, one pedicellate, the other 



