GRAMINEAE 375 



493. HOR'DElTlftl. L. 



[The ancient Latin name.] 



Spikelets 1 -flowered (with a subulate rudiment of second floret), 

 arranged in threes at the joints of the rachis, but the lateral ones 

 often abortive. Glumes collateral, lance-linear, rigid, subulate- 

 awned. Paleae herbaceous, the lower or front one convex, long- 

 awned at apex. Stamens included. Grain oblong, pubescent at 

 summit, usually adherent to the paleae. 



1. H. VULGXRE, L. Spikelets all fertile, and awried, arranged so 

 as to form a 4- (or somewhat 6-) sided spike. 



COMMON HORDEUM. Four-rowed Barley. 



Annual. OulmZto 3 feet high, smooth. Leaves 6 to 15 Inches long; sheaths 

 smooth, auriculate at throat. Spike about 3 inches long ; rachis pubescent on the 

 margins. 

 Hob. Fields. Nat of Sicilly and Tartary. Fl. May. Fr. June. 



2. H. DIS'TICHUM, L. Lateral spikelets abortive and awnless, the 

 fertile ones distichous, forming a 2-sided spike. 



DISTICHOUS HORDEUM. Two-rowed Barley. 



Annual. Oulm 2 to 3 feet high, smooth. Leaves 6 to 15 inches long; sheaths 

 smooth, auriculate at throat. Spike 3 to 4 inches in length; rachis hirsute on the 

 margins. 

 Bub. Fields. Nat. of Tartary. Fl. June. Fr. July. 



Obs. Both species were formerly much cultivated, in this County ; 

 but, of late, the culture seems to be transferred to western New 

 York. 



TRIBE 6. AVE V NEAE. 



Spikelets 2- or several-flowered, panicled, the terminal floret mostly abortive; 

 glumes and paleae membranaceous, or chartaceous, the lower palea mostly bear- 

 ing a bent or twisted awn on the back ; stamens 3. 



g 1. Lower palea 3- to ^nerved, thin and membranaceous. 



494. AI'RA, L. 



[An ancient Greek name, for another grass.] 



Spikelets 2-flowered, in an open diffuse panicle; florets small, both 

 perfect (often with an abortive third one), sometimes equalling, but 

 usually shorter than the membranaceous shining glumes. Paleae 

 nearly equal, hairy at base, the lower one 3- to 5-nerved, lacerate- 

 toothed at apex, awned on the back below the middle. Grain 

 oblong, smooth. Dry, wiry, slender grasses, with smooth culms, 

 and lead-colored glumes. 



1. A. caespltosa, L. Leaves flat, roughish ; lower palea 4- 

 toothed at the truncate apex ; awn short, and mostly straight. 

 CESPITOSE AIRA. 



Perennial. Culms 2 to 3 feet high, growing in tussMks. Leaves 6 to 15 inches 

 long, narrow, scabrous on the upper surface ; sheaths smooth ; ligide, elongated, 

 acuminate. Panicle oblong, at first contracted, finally diffuse ; branches semi-ver- 

 ticillatc, capillary, sharply scabrous ; florets as long or rather longer than the 

 bluish glumes. Grain free, not grooved. 

 HJ^I Moist places, on Serpentine rock : frequent there. Fl. May. Fr. July, 



