138 AYENA. 



[CLASS III. ORDER II. 



11. B. racemo'sus, Linn. (Fig. 178.) smooth Bromc-grass. Panicle 

 erect ; stalks unbranched ; spikelets sliglilly compressed ; florets 

 imbricated, smooth ; awns straight, about as long as the glumes ; 

 leaves slightly hairy. 



English Botany, t. 1079. English Flora, vol. i. p. 154. Lindley, 

 Synopsis, p. 311. Hooker, British Flora, vol. i. p. 52. 



Root small, fibrous. Stem erect, from one to two feet high, finely 

 striated, smooth, or slightly downy. Leaves linear, narrow, acuminated 

 at the point, striated, and slightly hairy. Sheaths rather long, close, 

 striated, smooth, or slightly downy. Ligula short, obtuse, torn. In- 

 florescence an erect or slightly drooping, close, simple panicle; its 

 branches simple, very rarely divided, angular, and slightly downy. 

 Spikelets similar to the last, except being quite smooth and less nume- 

 rously ribbed : this, together with the smaller and nearly unbranched 

 panicle, appear to be the only characters by which they can be distin- 

 guished from each other ; and it is doubtful if this is any more than a 

 variety depending upon difference in the situation of growth. 



Habitat. Fields and road-sides ; not unfrequent. 



Annual or biennial ; flowering in June and July. 



GENUS XLI. AVE'NA. LINN. Oat-grass. 



GEN. CHAR. Panicle loose. Spikelets two or more flowered. Glumes 

 two, nearly equal. Glumelles two, lanceolate, nearly equal ; the 

 outer bifid at the apex, and bearing a twisted dorsal awn. 

 " Name of doubtful origin ; the ancients applied it to the Brome- 

 grass. Oat, Theis tells us, comes from the Celtic word atan, the 

 oat; and that again from etan, to eat." Hook. 



1. A.fat'ua, Linn. (Fig. 179.) wild Oat. Panicle erect, spreading; 

 florets about three, roughish, and hairy at the base, shorter than 

 the glumes ; awn long and stout. 



English Botany, t. 2221. English Flora, vol. i. p. 163. Lindley, 

 Synopsis, p. 310. Hooker, British Flc^a,, vol. i. p. 53. 



Root fibrous, rooting from the lower joints. Stem erect, round, 

 smooth, striated, three or four feet high, leafy below, naked above. 

 Leaves broad, linear, flat, acuminated, numerously ribbed and striated, 

 rough, and sometimes hairy. Sheaths long, close, striated, thin, 

 smooth, or slightly hairy. Ligula short, obtuse, torn. Inflorescence a 

 large, spreading panicle; its branches in half alternate whorls, slender, 

 angular, rough, swollen at the base and upper extremity, simple or 

 branched. Spikelcts large, more or less drooping. Glumes large, 

 membranous, green, lanceolate, with a long point, which, as well as 

 the margins, are shining and pale ; ribs numerous, prominent. Flo* 



