GRASS FAMILY. 



29 



usually one of them bearing a bent or twisted awn; internodes between 

 the different bractlets or flowers not measurable. Palea usually 

 shorter than its bractlet, sometimes obsolete. Stamens usually 3, 

 rarely only 2 or 1. 



1. ANDROPOGON L. Sorghum. 



Our only species belongs to the sub-genus Sorghum, having the 

 stems hard and pithy; racemes solitary or in pairs, panicled; joints of 

 the rachis without a translucent line; bracts broad-lanceolate, finally 

 indurated and shining, awnless (in our species); lower bractlet empty, 

 or sometimes obsolete, much the smaller, hyaline; upper very slender, 

 awnless or with a geniculate awn; palea small, hyaline or obsolete. 

 Scales wedge-shaped. Stamens 3. Styles distinct. (Greek andros, a 

 man, pogon, a beard, having reference to the bearded callus of the 

 staminate spikelets in most species). 



1. A. Sorghum Brut. var. Halepensis Hackel. JoHNSON-GRASS, 

 Perennial, rootstock stout, creeping; stems stout, erect, 2 to 5 ft. high; 

 leaf-blades flat, with undulate margins, 8 to 24 in. long, \\ to 3 in. 

 wide, apex drooping; panicle variable 1 to 2 feet long, oblong-elliptical, 

 dense or rather loose, more or less drooping; branches mostly in 

 whorls of 4, rarely 2 or 6; sessile spikelets variable, lanceolate or 

 elliptical, 2 to 3 lines long; bracts equal; lower bract of the perfect 

 spikelet firm, more or less shining and often dark colored, obscurely 5 

 to 9 or 11-nerved; margins involute; upper 3 to 7-nerved: bracts of 

 the staminate spikelets narrow and more acuminate, the lower almost 

 2-keeled, with 2 prominent nerves near each margin; upper 5-nerved; 

 empty bractlet one-fourth shorter than the lower bract, elliptical- 

 oblong or oval, delicately 2-nerved; lower flower enclosing bractlet 

 one-half as long as the upper bract, broadly oval, obtuse, 2-lobed, 

 often bearing a short awn; anthers yellow, 1 to 1£ lines long; scales 

 fringed; pedicellate spikelets sometimes reduced to the bractlet, much 

 narrower than the fertile ones. — (Sorghum Halepense Pers.) 



Originally introduced into the United States as a forage plant, now 

 a troublesome weed in orchards and elsewhere. Sparingly naturalized 

 within our limits: Healdsburg; Lower Sacramento; Napa City; also in 

 the San Joaquin and Chino valleys. 



Tribe 2. Paniceae. Millet Tribe. 



Spikelets arranged in spikes, racemes or panicles, these sometimes 

 digitate or in pairs; rachis usually not jointed at the nodes and there- 

 fore not breaking up at maturity; pedicels jointed below the bracts 

 so that these fall away with the rest of the spikelet at maturity. 

 Spikelets terete or flattened on the back only, not at all laterally com- 

 pressed, all alike, either strictly 1-flowered, or with 1 perfect flower, 

 and a staminate flower, or bractlet and palea, or empty bractlet, 

 below it; lower bract usually much the smaller; perfect flower strictly 

 terminal, its bractlet and palea alike, cartilaginous, coriaceous, char- 

 taceous, or at least always firmer in texture than the bracts, awnless; 

 lower bractlet sometimes similar in texture to the bracts, sometimes 

 short-awned. 



