1 



596 CLXI. GRAMINE^. Agrostis. 



5. A. STRiCTA. Michx. Upright Aristida. 



SI. strictly erect, coespitose, branched, 2 — 3f high; Ivs. straight, erect, 

 pubescent, linear, convolute above ; panicle long, loosely racemose; spikelets ap- 

 pressed ; glumes unequal, very acute ; lower palea, hairy at base ; awns, twice as long 

 as the paieoc, spreading, the middle one the longest. — % Penn. to Car.W. to Mich. 



2. STIPA. 



Lat. stl'pa, a foot-stalk ; alluding to the stipitate fruit of some of the species. 



Glumes 2 ; paleae mostly 2, shorter than the glumes, the lower 

 with a long awn at the apex, the upper entire ; awn jointed at the 

 base, deciduous ; caryopsis striate. 



1. S. AVENACEA. Feather Grass. 



St. naked above ; 2 — 3f high; Ivs. smooth, striate, setaceous, chiefly radi- 

 cal ; panicle spreading, somewhat 1-sided, 4—6' long, at length difluse, branches 

 capillary, solitary and in pairs ; glumes nearly equal, mucronate, as long as the 

 dark brown, cylindric fruit ; scales 2, lanceolate ; awn twisted, 2 — 3' in length. — 

 %. N. Y. to Car. 



2. S, JUNCEA. Pursh. Rush-leaved Feaiher Grass. 



St. 2 — 3f high ; Ivs. convolute-filiform, smooth inside, long; panicle loose j 

 glumes loose, filiformly acuminated to more than twice the length of the fruit ; 

 fr. attenuated at base into a stipe which is a third of its length, stipe acute, 

 pubescent ; palece obtuse, distinctly articulated to the awn, which is smooth and 

 slender, scarcely contorted and 4 — 6' in length. — % Prairies, 111., Mo. When 

 in fruit, the pungent stipe adheres to everything that comes in its way, Aug. 



3. S. Canadensis. Lam. 



Lvs. setaceous ; j^anicle small ; glumes smooth, ovate-obtuse, as long as 

 the pubescent fruit ; aicn thick and short. — % Amherst, Mass. Dewey. Neither 

 this nor the preceding species is common or of much value in agriculture. 



3, PIPTATHERUM. Palis. 



Ch\ ninrci}, to fall, ^epos, harvest. 



Panicle racemed ; glumes membranaceous, longer than the ellipti- 

 cal, cartilaginous palese ; loiver palea awned at the tip ; scales ovate, 

 entire ; caryopsis coated. 



P. NIGRUM, Torr. (Oryzopsis melanocarpa, Muhl.) Black-seeded Millet. 

 St. erect, simple, leafy, 18 — 24' high ; panicle simple, flexuous, few- 

 flowered ; spikelets racemose, ovoid-lanceolate ; glumes acuminate, mucronate, 

 5 — 6" in length, smooth ; palea hairy, nearly black when ripe, the lower one 

 tipped with an awn an inch in length ; fruit black, — 1\. Rocky hills, N, Eng. 

 to Ky,, frequent, Aug, 



4. ORrZOPSlS. Rich, 

 Named for its resemblance (oi//i j) to the genus Oryza. 



Panicle racemed ; glumes 2, subequal, loose, obovate, awnless ; 

 paleae 2, cylindric-ovate, hairy at base ; scales linear-elongated. 



O. asperifolia. Michx. Mountain Rice. 



St. nearly naked, purple at ba.se, 10 — 20' high; lvs. subradical, erect, 

 rigid, pungent at the point, nearly as long as the stem, cauline ones few and 

 very short ; spikelets in a racemose, simple, flexuous panicle, 1 — 2 upon each 

 branch ; glumes abruptly acuminate ; pale(s white, the lower one with a long 

 bent awn. — Woods, Free States, N. to Subarctic Am. Leaves green through 

 the winter, Caryopsis white, about as large as rice, farinaceous. May. 



Tribe 2, AGROSTIDE^.— Inflorescence panicled, rarely spiked, Spike- 

 lets solitary, 1-flowered. Glumes and paleas of nearly similar texture, usu- 

 ally carinate. 



5. AGROSTIS, 



Gr. aypos, a field ; it being eminently an occupant of fields and pastures. 



Inflorescence paniculate ; glumes 2, acute, subequal, the lower one 



