ORDBE 156. GRAMINE^E. 801 



brakes and scarcely ever flower. The firm, jointed, hollow, straight and tall 

 culms are variously useful. 



47. LEPTITRUS, Br. Spikelet 1 on each joint of the filiform rachis, 

 immersed in a cavity, 1 or 2-flowered | glumes coriaceous, acute, the 

 lower often wanting; pales membranous, awnless, shorter than the 

 glumes ; grain free. Lvs. and spikes very narrow, 



L. paniculatus Nutt. Culm scarcely If, compressed ; Ivs. short, rigid, sheathing 

 the base of the panicle ; pan. or naked rachis incurved, acutely triangular, rigid, 

 bearing 610 compressed, subulate spikes on one side, each 1 2' long; spike- 

 lets remote, on one side the rachis ; glumes rigidly fixed, unequal, parallel ; paleae 

 2, the outer of the same texture as the glumes, inner membranaceous. 111. (Mead), 

 Mo. (Nuttall). 



48. HOR'DEUM, E. BARLEY. (The ancient Latin name.) Spike- 

 lets 3 at each joint of the rachis, 1-flowered, tho lateral ones sometimes 

 abortive ', glumes 2, subulate, nearly equal, awned ; palea3 2, lower 

 lance-ovate, long-awned, upper obtusely acuminate ; caryopsis adhering 

 to the paleae. 



1 H. vulgare L. FOUR-ROWED BARLEY. Culm smooth, 2-^3f; Ivs. lance-lin- 

 ear, carinate, nearly smooth ; sheaths auriculate at the throat ; Gpike thick, about o' 

 long ; spikelets all fertile, 1-flowered. with an awn-like rudiment at the base of 

 the upper palea ; glumes collateral, shorter than the flowers ; fr. arranged in 4 

 rows. li Extensively cultivated. May. 



2 H. distichum L. TWO-ROWED BARLEY. Culm 2 3f; Ivs. lance-linear, 

 scabrous above ; sheaths auriculato at the throat ; spike 3 i 1 lon^, linear, com- 

 pressed ; lateral spikelets abortive, awnless ; fr. arranged in 2 rows. ,'i) Morn 

 common, and is generally preferred for malting to the former species. June. 



3 H. jubatum L. SQUIRREL-TAIL GRASS. Culm slender, round, smooth, simple, 

 about 2f; Ivs. broad-linear, 4 6' long, rough-edged, otherwise smooth, as well 

 aa the sheaths ; spikes 23' long spikelets with tho lateral flowers neuter ; 

 glumes and paleae produced into fine, smooth awns, 6 times as long (2') as the 

 flowers ', abortive flowers on short pedicels. () Marshes, N. Eng. to Mo., N. to 

 Subarc. Am. June. 



4 H. pusillum Xutt Culm 4 6', decumbent or geniculate at the base; Ivs. 

 about !' long, rather obtuse, glaucous, striate; upper sheath tumid, embracing 

 the spike; spike linear, about 1J' long; glumes by 3s, collateral, imbricated, 

 lateral ; abortive fls. awnless ; awn of the central sessile ? , as long as those of the 

 involucre, twice the length (7") of the paks, glumes all awned, the inner setaceous 

 from the base. Ohio to 111. and Mo. 



49. EL'YMUS L. LYME GRASS. WILD RYE. (Gr. eAvw, to en- 

 velop ; as the spike in the sheath.) Spikelets 2 to 4 at each joint of 

 the rachis, 2 to 6-flowered ; glumes 2, subequal, subulate, both placed 

 on the outer side of their spikelet forming an involucre to the group, 

 sometimes minute or obsolete ; pales lanceolate, coriaceous, the lower 

 mostly awned. 



ELTMTS proper. Involucre present, consisting of the conspicuous glumes (a) 



a Spikelets 1 to 5-flowered, hard, rough, with conspicuous awns, (b) 



b Spikelets glabrous, merely rouifh, 2 or 3-flowereil JNos. 3, 1 



b Spikelets hispid with hairs, 1 to 3, or 2 to 5-flowered Nos. 8, 4 



a Spikelets 5 to S-flowered. soft-pubescent, without awns No. 5 



GYMNOSTACHUM. Invol. obsolete or the gls. minute. Awns divaricate No. 6 



1 E. Virginians L. Culm smooth, 3 or 4f, erect ; Ivs. lance-linear, flat, scabrous, 

 deep green, 4" broad; sheaths striate ; lig. very short ; spike erect, thick, 3 to 6' 

 long ; apikelets in pairs, 2 or 3-fiowered, the collateral glumes in front, thickened 

 and subconnate at base, striate, and with the pales, produced into rather short (6 

 to 10"), scabrous awns. ^-11 Banks of streams, U. S. A Southern variety has 

 the glumes very thick aad arcuate at base (like E. Caput- Medusa? L.). Aug. 

 51 



