Trisetum. GRAMINE^E. 295 



lUM'ved. Florets herbaceo-chartaceous, becoming firmer tliaii tlie glumes, upon a 

 liairy-beardcd rhacliis. Lower palct rounded on tlie liark, r» - 1 1-nerved, acutely 

 2-cleft at tip, bearing from between the teeth a long bent or twisted awn which pro- 

 ceeds from the midnerve only. Upper palet eiiualling the lower, minutely bilid. 

 Stamens 3. Scales 2, bilid at apex. Ovary hairy above : styles short, distant ; 

 stigmas densely plumose. Grain cylindrical-oblong, deep-grooved, hairy throughout 

 or at the tip only, closely invested by tlie upper palet. 



A gpiuis of about 30 annual and iinn'nnial sppuics, l)c'l(ingin<,' to tcniperatn and cold regions. 

 Two s|»'cies are found in tlie Easleiii States. Tiisclnm and Arrhcnalherum are by some botanists 

 included as sections of this genus. 



1. A. fatua, Linn. An erect annual, 2 or 3 feet high, smooth except at the 

 hairy nodes, witli liat slightly scabrous leaves and loose sheaths: panicle 8 to 10 

 inches long, the few-tlowered rays spreading equally; spikelcts aljout an inch long, 

 the scarious pointed glumes longer than the florets, often purplish at base : lower 

 palet about G lines long, lirm at base, scabrous and covered with long brown hairs, 

 its lobes tapering to a sharp point ; awn about twice the length of palet, l)ent near 

 the middle and twisted below : grain very hairy. — Kunth, Enum. i. 302, and 

 Suppl. 250; Lentil. Illust. Lrit. Flor. t. 1179; Watson, Lot. King. Expe<l. 392. 



Common in fields. Probably a native of the Mediterranean region, but naturalized in many 

 grain -growing countries, including South America and Australia. As the " Wild Oat " it is 

 highly valued for hay. It is supposed to be the original of the cultivated oat {A. saliva), which 

 is said to readily degenerate into this. Professor Buckman of Englantl gives a detailed account 

 of having produced fiom the seeds of this a good variety of smooth cultivated oat in a few years' 

 successive sowing and selection. 



34. TRISETUM, Beauv. 



Panicle mostly narrow, loose or dense and even spike-like. Spikelets 2- (rarely 



3- or more-) flowered. Glumes unequal, acute, keeled, membranaceous with scarious 



margins, the lower Lnerved, upjjcr (sometimes both) 3-nerved. Florets more or less 



separated by the hairy joints of the rhachis, the last one of wiiich extends beyond 



the upper spikelet as a rudiment, sometimes bearing an imperfect floret. Palets 



similar in texture to the gliiniea, the lower keeled, r)-nerved, acute, more or less 



deeply bifid, bearing above the middle an awn whi(!h proceeds from the midnorvo, 



usually twisted at tlio base and bent near the middle. Upper palet 2-nerved and 



2toothed. Ovary hairy or smooth : styles stigmatic from near the base. Grain 



smooth, not furrowed. 



Over 60 species have been described, having a geographical range similar to Avena, to which 

 some authors imite it. Two species belong to the Atlantic States. 



* Panicle open with elonrjated rays : ovary hairy at the apex. 



\. T. cernuum, Trin. Culm 2 or 3 feet high, with flat leaves about 6 inches 

 long and nearly half an inch wide : panicle 6 to 10 inches long, very open, nodding 

 above ; rays in distant clusters, cernuous, capillary, roughened, flower-bearing above 

 the middle; spikelets 2-3- (rarely 4-) flowered: lower floret with a short-beaixled 

 callus, the others spreading, distant, upon hairy joints half as long as the florets : 

 glumes very unequal, the lower narrow, subulate, less than one-half tlie length of the 

 broad 3-nerved obtuse and mucronate upper one : lower palet about 3 lines long, 

 slightly scabrous especially above, bearing a slender awn twice its own length, and 

 terminating in two subulate teeth, which bear sct;e nearly a line long ; uppermost 

 joint of the rhachis with a long weak awn. — Mem. Acad. St. Petersb. 1831, Gl ; 

 Hook. Fl. Lor. -Am, ii. 244. Avemi cermia, Kunth, Enum. i. 30G; Griseb. in Ledeb. 

 Fl. Eoss. iv. 419. 



