GRAMINEAE. 7 1 



sessile spikelets 9-10 mm. long, the outer 2 scales hispid on the nerves toward the 

 apex, pubescent toward the summit with long loose-crisped hairs; pedicellate spike- 

 let similar to the sessile one, staminate. In dry soil, Mont, and Neb. July. 



5 . AMPHILOPHIS Nash. 



Perennial grasses with usually flat leaves and showy, often silvery-white, pan- 

 icles, the axis short, making the panicle appear fan-like, or elongated with the 

 branches more scattered. Racemes usually numerous, the internodes with mani- 

 festly thickened margins, the median portion thin and translucent, the pedicels of 

 the same structure, the margins ciliate with usually long hairs. Sessile spikelets 

 of 4 scales, the first one 2-keeled, the second i -keeled, the third and fourth scales 

 hyaline, the latter very narrow, stipe-like, somewhat thickened, gradually merg- 

 ing into a usually geniculate, contorted or spiral awn, or the awn rarely wanting. 

 Pedicellate spikelets staminate and similar to the sessile, or sterile and smaller 

 than them. Stamens 3. Styles distinct. Stigmas plumose. Grain free, enclosed 

 in the scales. [Greek, in reference to the hairs surrounding the spikelets.] About 

 30 species, in temperate and tropical countries. 



i. Amphilophis Torreyanus (Steud.) Nash. TORREY'S BEARD - GRASS. 

 (I. F. f. 223.) Culms erect, 4.5-10.5 dm. tall, the nodes naked. Sheaths more 

 or less glaucous; leaves 7.5-17.5 cm. long, glaucous; spikes 2.5-3.75 cm. long in 

 a terminal long-exserted panicle 4-10 cm. long; outermost scale of sessile spikelet 

 3-4 mm. long, about equalling the terminal hairs of the rachis-joints, lanceolate, 

 acute; awn 8-16 mm. long, spiral; pedicelled spikelet rudimentary. In dry soil, 

 Kans. to Ariz, and Mex. Aug. -Sept. (Andropogon Torreyanus Steud.) 



6. SORGHASTRUM Nash. 



Generally tall grasses, ours perennials, with long, narrow, flat leaves and termi- 

 nal panicles. Spikelets in pairs, or 3*3 at the end of the branches, one sessile and 

 perfect, the lateral pedicelled, empty, or reduced to the pedicel only. Perfect 

 spikelet consisting of 4 scales, the two outer indurated and shining, the inner 

 hyaline, tlie fourth awned and subtending a palet and perfect flower, or the palet 

 sometimes wanting. Stamens 3. Styles distinct. Stigmas plumose. Grain free. 

 [Named in reference to its resemblance to sorghum.] About 15 species, in tem- 

 perate and tropical countries. (Chrysopogon Benth. Not Trin.) 



i. Sorghastrum avenaceum (Michx.) Nash. INDIAN GRASS. (I. F. f. 224.) 

 Culms 9-24 dm. tall. Lower leaves 3 dm. or more in length; panicle 1-3 dm. 

 long, brownish -yellow; branches 5-10 cm. long, erect-spreading ; spikelets erect 

 or somewhat spreading ; first scale of sessile spikelet 6-8 mm. long, pubescent 

 with long hairs; second scale glabrous; awn 1-2 cm. long, the column having but 

 a single bencl ; lateral spikelets wanting. In dry fields, Ont. to Man., south to 

 N. H., Fia. and Ariz. Aug. Sept. {Chrysopogon az'enaceus Benth.) 



7. SORGHUM Pers. 



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 subtending 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. 



x. Sorghum Halepense (L.) Pers. JOHNSON-GRASS. (I. F. f. 225.) Culms 

 9-20 dm. tall; sheaths smooth; leaves 3 dm. or more long, 6-25 mm. wide; panicle 

 from 1.5-4.5 dm. long; outer scales of sessile spikelet 4-6 mm. long, usually purplish, 

 pubescent with long appressed hairs; awn when present 8-16 mm. long. In fields 

 and waste places, southern Pa. to Mo. and Kans., south to Fla. and Tex. Native 

 of southern Europe and Asia. July-Sept. 



8. NAZIA Adans. 



An annual grass, diffusely branched, with flat leaves and I -flowered decid lous 

 spikelefs, either solitary or in clusters of 3-5 in a terminal spike. Scales of spikelet 

 2 or 3, the outermost small or wanting, the second rigid and covered with hooked 

 prickles, the third membranous, subtending a palet and perfect flower. [Name 



