MANUAL OF THE GRASSES OF THE UNITED STATES 



775 



grown especially in Oklahoma and 

 Illinois, furnish the material for 

 brooms. The other forms are grown 

 for forage or for the seed which is 

 used for feed. Chicken corn (S. vul- 

 gare var. drummondii (Nees) Hack, 

 ex Chiov.), described from New 

 Orleans, La., was early introduced 

 from Africa and became naturalized 

 in Mississippi and Louisiana, but is 

 apparently dying out. Culms up to 

 2 m. tall; blades to 5 cm. wide; panicle 

 elongate, narrow but loose. Near rail- 

 way, Illinois; weed in cotton field, 

 Alabama; Mississippi; California; 

 rare. 



The differences between most of 

 the varieties are so indistinct and so 

 unstable because of intercrossing as 

 to make it very difficult to assign 

 descriptive limits. The application of 

 botanical names is uncertain, and it 

 seems best, therefore, not to assign 

 to them definite varietal or specific 

 Latin names. 



The following names have been 

 applied in American literature to 

 some of the more important varieties. 



Kafir. S. vulgare var. caffrorum (Retz.) 

 Hubb. and Render. 



Shallu. S. vulgare var. roxburghii (Stapf) 

 Haines. 



Durra. S. vulgare var. durra (Forsk.) 

 Hubb. and Rehder. 



Broomcorn. S. vulgare var. technicum 

 (Koern.) Jav. 



Sorgo. S. vulgare var. saccharatum (L.) 

 Boerl. 



Tunis grass (S. virgatum (Hack.) 

 Stapf) is a tall annual with a narrow 



slender open panicle and narrowly- 

 lanceolate green finely awned spike- 

 lets. Africa. Has been tried at experi- 

 ment stations, but has not been 

 brought into commercial cultivation, 

 being inferior to Sudan grass. 



Sorghum lanceolatum Stapf. Ro- 

 bust annual to 1.5 m. tall; blades 

 30 to 60 cm. long, 2 to 3.5 cm. wide; 

 panicle 25 to 40 cm. long with as- 

 cending branches; rachis joints and 

 pedicels ciliate; spikelets about 6 

 mm. long, silky-pubescent, becoming 

 glabrous and shining on the lower 

 half; awn about 1 cm. long. O — 

 Becoming a weed at Yuma, Calif. 

 Introduced from tropical Africa. 



Sorghum sudanense (Piper) Stapf. 

 Sudan grass. Annual, branching 

 from the base, 2 to 3 m. tall; blades 

 15 to 30 cm. long, 8 to 12 mm. 

 wide; panicle erect, loose, 15 to 30 

 cm. long, about half as wide, the 

 branches subverticillate, the lower 

 half or third naked; sessile spikelet 

 6 to 7 mm. long, lanceolate-ovate, a 

 ring of hairs at base, sparsely ap- 

 pressed-silky toward the apex; awn 

 persistent, 10 to 15 mm. long, genicu- 

 late, twisted below; pedicellate spike- 

 let narrow, about as long as the 

 sessile spikelet, strongly nerved. O 

 (Sorghum vulgare var. sudanense 

 Hitchc.) — Extensively cultivated for 

 pasture and hay and escaped in the 

 Southern and Midwestern States 

 and in Arizona and California. Orig- 

 inally from Anglo-Egyptian Sudan. 



157. SORGHASTRUM Nash 



Spikelets in pairs, one nearly terete, sessile, and perfect, the other wanting, 

 only the hairy pedicel being present; glumes coriaceous, brown or yellowish, 

 the first hirsute, the edges inflexed over the second; sterile and fertile lemmas 

 thin and hyaline, the latter extending into a usually well-developed bent and 

 twisted awn. Perennial, erect, rather tall grasses, with auricled sheaths, narrow 

 flat blades, and narrow terminal panicles of 1- to few-jointed racemes. Type 

 species, Sorghastrum avenaceum (Michx.) Nash (S. nutans). Name from Sor- 

 ghum and the Latin suffix astrum, a poor imitation of, alluding to the resem- 

 blance to Sorghum. 



The most important species, S. nutans, is a common constituent of wild or 

 prairie hay in the eastern part of the Great Plains region. 



Awn usually 15 mm. long or less, once geniculate. Panicle rather dense, yellowish. 



1. S. NUTANS. 



