104 



GRAMINEAE. 



j. Chrysopogon avenaceus (Michx.) Benth. Indian Grass. (Fig. 224.) 



Andropogon avenaceum Michx. Fl. Bor. Am. i: 58, 

 1803. 



Sorghum nu tans A. Gray, Man. 617. 1848. 



Sorghum avenaceum Chapm. Fl. S. States, 583. 

 1860. 



Chrysopogon avenaceus Benth. Journ. I^inn. Soc. 

 "19: 73. 1881. 



Culms erect, 3-8 tall, from creeping root- 

 stocks, smooth, the nodes pubescent. Sheaths 

 smooth ; lower leaves i or more in length, 

 2 // -S // wide, long-acuminate, scabrous ; panicle 

 4 / -i2 / long; branches 2^-4' long, slender, erect- 

 spreading; spikelets in pairs, or in 3's at the ends 

 of the branches, erect or somewhat spreading ; 

 first scale of sessile spikelet 3 // -4 // long, acute, 

 pubescent with long hairs ; second scale glab- 

 rous ; awn 5 // -io // long, the column very little 

 if at all bent ; lateral spikelets reduced to 

 plumose pedicels. 



In dry fields, Ontario to Manitoba, south to 

 Rhode Island. Florida and Arizona. Panicle brown- 

 ish-yellow. Aug.-Sept. 



Chrysopogon nutans (!,.) Benth., distinguished from this species by its longer awn (i2"-i5" 

 long), supported on a column distinctly bent at about the middle, occurs in Tennessee and is 

 said to have been recently found in Kentucky. 



6. SORGHUM Pers. Syn. i: 101. 1805. 



Annual or perennial grasses with long broad flat leaves and terminal ample panicles. 

 Spikelets in pairs at the nodes, or in 3*3 at the ends of the branches, one sessile and perfect, 

 the lateral pedicelled, staminate or empty. Sessile spikelet consisting of 4 scales, the 

 outer indurated and shining, obscurely nerved, inner hyaline, the fourth awned and sub- 

 tending a small palet and perfect flower, or palet sometimes wanting. Stamens 3. Styles 

 distinct. Grain free. [Name Indian.] 



About 13 species, of wide distribution in tropical and warm-temperate regions. 



i. Sorghum Halepense (L,.) Pers. Johnson-grass. (Fig. 225.) 



Holcus Halepensis L. Sp. PI. 1047. 1753. 

 Andropogon Halepensis Brot. Fl. Lusit. i: 89. 

 Sorghum Halepense Pers. Syn. i: 101. 1805. 



1804. 



Culms erect, 3-5 tall, simple or sometimes 

 much branched, smooth and glabrous. Sheaths 

 smooth; leaves i or more long, X /-I/ wide, 

 long-acuminate ; panicle open, from X-i>< 

 long, the generally whorled branches spreading 

 and naked towards the base ; outer scales of ses- 

 sile spikelet 2"-3" long, ovate-lanceolate, usually 

 purplish, pubescent with long appressed hairs ; 

 awn when present 4"-8" long, more or less bent; 

 pedicelled spikelets of 4 scales, the outer two 

 about 3" long, membranous, 7-9-nerved, their in- 

 rolled margins ciliate, the inner two shorter and 

 narrower, hyaline, sometimes with staminate 

 flowers. 



In fit-Ids :md waste places, southern Pennsylvania 

 t., HiMouii, totttfa t.. I-lurida and Texas. Widely dis- 

 tributed by cultivation in tn.pii-al Aim-rica. Native 

 of southern Kurope and Asia. July-Sept. 



