m CLXI. GRAMINE^. SETARU 



12. P. DICHOTOMUM. 



St. much branched and dichotomous above, erect or decumbent, 1- 2i 

 high, branches fasciculate ; Ivs. linear-lanceolate, smooth, very numerous, 1 2' 

 long, ciliate at base ; panicles lateral and terminal, simple, capillary, with loose, 

 spreading branches ; spikelets minute, ovoid-obtuse. Varies with the stem very 

 tall, or low, and decumbent ; rather rigid or very slender. N. Eng. to Ky. July. 



13. P. NITIDUM. Lam. (P. discolor. Muhl.} 



St. erect, slender, 8 24' high, the nodes with a ring of dense, deflexed 

 hairs ; Ivs. lance-linear, narrow, acuminate, rather remote, 2 i' by 2 4" ; 

 sheaths as long as the leaves, hairy at the throat and often all over ; slip. ; pan- 

 icle rather small, exserted, roundish-ovoid, diffuse, nearly glabrous, branches 

 spreading ; spikelets purplish, numerous, small (" long), oblong, obtuse ; lower 

 glume minute ; abortive fl. neutral, its outer palea equaling the upper glume ; $ 

 white, polished. % 1 Woods and fields, U. S. June. 



a. Tall, simple, smooth, except the densely bearded nodes. Middle and 

 Western States. 



/?. St. with short branches ; Ivs. and sheaths pubescent. N. Eng. and Middle 

 States, common. 



y. Low, branched, very hairy, purplish. Dry fields, N. Eng., common. 

 These are the extreme forms, between which there are many intermediate ones. 



14. P. MICROCARPON. Muhl. Darl. 



St. 18 30' high, erect, simple, glabrous ; joints glabrous ; Ivs. lanceolate, 

 veined, ciliate at base, undulate and scabrous on the margin, scabrous above, 

 smooth beneath, 6 10" wide ; sheaths deeply striate, smooth ; stip. ; panicle 

 large, much branched, nearly smooth ; spikelets small, numerous, scarcely pu- 

 bescent; Q flower as long as the upper glume;//-, shining, bluish-white. 1\. 

 Woods and low grounds, Penn. Darlington. 



15. P. CAPILLARE. Annual Field Panic. 



St. nearly simple, assurgent and thick at base, 1 2f high ; Ivs. hairy, 

 broad-linear, acuminate, 4 6' long ; sheaths covered with hispid hairs ; panicle 

 large, pyramidal, capillary, loose, expanding ; spikelets small, purple, lanceo- 

 late, acuminate, smooth, on long, hispid peduncles -^abortive fl. of 1 palea. 

 Fields and roadsides, U. S. Aug. 

 P. -sylvaticum. Torr. St. very ^slender, branched at the base. Woods. 



1G. P. VERRUCOSUM. Muhl. (P. debilis. Ell.) 



St. slender, decumbent and geniculate, branching from the base, 1 2f 

 high ; Ivs. linear, a few inches long, spreading, smooth ; panicle much expand- 

 ed, few-flowered, flowers verrucose; abortive flower of one palea, and neuter. 

 1 Swamps and thickets, Mid. and S. States. Panicle terminal and lateral, 

 loose and capillary. Aug. 



17. P. VIRGATUM. Salt-lick Panic. 



Glabrous and often purple ; st. 3 5f high ; Ivs. long, linear-lanceolate, 

 hairy at base ; sheaths striate ; stip. with long, white ciliae ; panicle virgate, at 

 length spreading, diffuse, very large ; fls. acuminate, and with the glumes, 

 divaricate, paleas of the abortive flower nearly equal, enfolding the purple sta- 

 mens. 7|_ Salt-lick prairies, fields, &c., N. Y. to Ind. ! Aug. None of these 

 species are of much value in agriculture. 



22. SET ARIA. Palis. 



Lat. seta, a bristle ; from the bristly involucres of the spikelets. 



Inflorescence a compound, cylindrical spike ; spikelets 2-flowered, 

 invested with an involucre of 2 or more bristles ; glumes, flowers, 

 palese and fruit as in the genus Panicum. 



1. S. VIRIDIS. Palis. Wild Timothy. 



St. smooth, 2 3f high; Ivs. lanceolate, flat, minutely serrulate; sheaths 

 striate, hairy on the margin, and with a setose stipule ; spike cylindric, com- 

 pound, terminal, green ; involucre of 4 10 fasciculate bristles, much longer 

 than the spikelets ; palea of the perfect flower longitudinally striate, punctate. 

 (D Common in cultivated grounds, Free States. July, Aug. 



