166 TRIANDKIA— DIGYNIA. Avena. 



nute erect bristles : tumid and angular at the summit; the 

 lowest divided, or branched ; the rest sim|)le, erect, often very 

 short and thick. Spikelets erect, an inch long at most. Calyx- 

 valves lanceolate, concave, each with 3 princi])al rough ribs, the 

 points acute, thin and pellucid. Florets 5 or C, two-ranked, ra- 

 ther distant, each subtended by a large tuft of bristly hairs, 

 slightly decurrent, but the rest of the partial stalk is nearly 

 naked. Outer valve of the corolla much like the calyx, but 

 somewhat rougher, and 5 -ribbed ; deeply cloven at the point. 

 Awn terminating the keel about the middle of the glume, brown, 

 rough, partly silky ; its lower half strongly twisted when dry j 

 upper bent variously, taper-pointed. The in)2er valve is lanceo- 

 late, extremely thin, flat, with finely downy, not inflexed, edges, 

 nor any traces of ribs ; the point acute, torn, not cloven. 

 A specimen from Professor Schrader of his A. planiculmis proves 

 different from our plant j having a strong widely-creeping root ; 

 the stem, as well as the sheaths, which clothe its lower part, 

 compressed ; leaves much broader, and all flat ; panicle a span 

 long, more compound, variegated with purple ; spikelets one 

 third smaller ; and the hairs on their partial stalks much less 

 tufted. 



6. K.flavescens. Yellow Oat-grass^ 



Panicle much branched, spreading, erect. Florets about 

 three, longer than the very unequal calyx. Leaves flat, 

 a little downy. Root somewhat creeping. 



A. flavescens. /J»?z. S;>. P/. 1 18. Willd.v. 1.449. FLBr. 142. 



Engl. Bot. vA'i.t. 952. Curi. Loud. fasc. 3. t.5. Knapp t. 89. 



Hook. Scot. 44. S'incl.39. Schrad. Germ. v. \. 377. Host Gram. 



v, 3. 26. t. 38. Schreb. Gram. v. 1 . 76. t. 9. Leers 44. t. 10./. 5. 



Ehrh. Calam. 56. 

 A. n. 1497. Hall. Hist. v. 2. 233. 

 Gramen avenaceum pratense elatius, panicula flavescente, locustis 



parvis. Raii Syn. 407. Scheuchz. Agr. 223. t. A. f. 18. 

 G. avenaceum, panicula flavescente, locustis parvis, Moris, v. 3. 



2\b.sect.Q. t.7.f.42. 



In meadows, pastures, and by road sides, in chalky and hmestone 

 countries, frequent 5 sometimes on dry sandy soils. 



Perennial. July. 



Root more or less creeping. Stems a foot high, leafy, smooth, ra- 

 ther slender, with several, sometimes hairy, joints. Leaves nar- 

 row, taper-pointed, flat, hairy on both sides, many-ribbed. 

 Sheaths ribbed, besprinkled with deflexed hairs. Stipula .short, 

 jagged, fringed. Panicle rather close, half-whorled, sometimes 

 a little drooping, of innumerable small, yellowish, shining spike- 

 lets ; having sometimes AJlorets, instead of 2 or 3, in which case 

 their size is evidently increased. Calyx-valves acute, very un- 



