126 TRIANDRIA. DIGYNIA. danthonu. 



Root perennial. Culm somewhat cespitose at the base, a foot and 

 a half or 2 feet higli, slender, erect. Lower leaves numerous, 

 flat or involute, 6 — S inches iontj, hairy on the upper surface ; 

 tliose on the culm much shorter, erect. Sheaths very short. 

 Stifiule almost wanting, ciliate. Panicle about 2 inches long, 

 spiked ; lower branches a little divided. Sfiikelets at first te- 

 rete, but at length spreading. Calyx a third longer than the 

 florets; glumes nearly equal, lanceolate, very smooth, with 

 5 confluent nerves ; point much attenuated. Inferior valve of 

 the corolla obscurely 7-nerved, clothed with long hairs ; mar- 

 gins produced into 2 subulate teeth; awn about twice the 

 length of the valve, flat, carinate, twisted on the lower part ; 

 superior valve closely appressed, ciliate. Stamens 3 ; anthers 

 yellow. Sti<^mas white. JVectaries oval, obtuse. Seed oblong, 

 compressed, a little corrugate ; apex slightly 2-horned. 



Hab. In dry open woods and in sandy fields. June — July. 



The AvENA glumosa of Mi c hau x and Mu hlenber g 

 (D. sericea jYu 1 1.) appears to be only a variety of ^his species. 

 It is chiefly distinguished by its shining, very villous coi-olla, 

 and the long setaceous points of the superior'valve. The genus 

 Danthonia is nearly allied to Trisetum, but differs much in 

 habit. 



36. TRISETUM, Per so on. 



Calyx 3 — 5-flowered, membranaceous, as long as 

 the florets. Inferior valve of the corolla with 2 bristle- 

 form teeth at the tip, awned below the division of the , 

 teeth. Pers. Syn. I. p. 97. Bo em. is" Schult. 

 Gm. 327. P. de Beauv. t. XVIII. f. 1. Aven^ 

 spp. jL., Trin., he. Panicle compound. 



1. T. palustre'^: panicle contracted, nodding, somewhat 

 verlicillate ; calyx 2 — 3-flowered ; florets smooth, acuminate j 

 the inferior one awnless; inferior valve of the superior floret 

 bicuspidate, awned below the tip. Avena palmtris M ic h. 

 Fl.\.ip.T2. Pursh Fl.].^.Q6. M uh I. Gram. p. IB6. 

 Roem. ir Schult, II. p. 683. Aik\ pallens M uhl. \. c» 

 p. 84. Spreng. Mant. I. Tp. 33. E I li o 1 1 Sk. l.p. 15]. 

 Roem. ir Schult. II. p. 673. 



Root perennial. Culm 1 — 2 feet high, erect ; nodes contracted. 

 Leaves flat, 2 — 3 inches long, and, with the sheaths, smooth. 

 Stifiule short, retuse. Panicle with the lower branches in fives. 

 Sfiikelets all on long peduncles, much compressed, generally 

 2-flowered, with an abortive pedicel. Calyx unequal, acumi- 

 nate and mucronate ; glumes 3-nerved, scabrous on the keel ; 

 the superior one a little longer. Sufierior Jloret on a shoit 

 hairy pedicel ; inferior valve lanceolate, acuminate, terminated 

 by 2 short bristles, a little below which is inserted a twisted 

 .To/Ti the length of the valve ; superior valve half the length o^ 



