394 



ORDER 155. GRAMINE.E. 



2 O. Walterl (Ell). Culms slender, 2f; Ivs. narrow and sheaths glabrous; spikes 



one-sided, Jl' long, alternate ; glumes hispid, pointed ; the fls. somewhat pointed 

 the sterile with 3 stamens. Low grounds, Car. to Fla., and La. July. 



3 O. hlrtellus R. & S. Decumbent, branched, ciliate; Ivs. lanceolate, 1 2' by 



4 6" ; spikes erect, remote, one-sided, J' long, few in the perfectly simple panicle ; 

 pale long-awned, glumes short-awned. Woods, South. Aug. Oct. 



23. SET ARIA, Beauv. BRISTLY FOXTAIL. Fls. 

 in cylindric spikes or spike-like panicles. Spike- 

 lets each subtended by a cluster of awn-like bris- 

 tles (abortive pedicels) forming a bristly involucre. 

 Otherwise a? in Panicum. July, Aug. 



Bristles rough backward, in pairs, short No. 1 



Bristles rough upward. ... (a) 



a 4 10 in each involucre Nos. 2 4 



a 13 in each involucre Nos. 57 



1 S. vertlclllata Beauv. Spicate pan. 23', composed 

 of short divided branchlets seeming in many verticils ; 

 bristles little longer than the spikrlets : fruit-pales 

 rongh-pnnctate. Culm if. T) N. Eug. to Car., and \\'. 



2 S. filauca Beauv. Bottle G. Spike cylindric, yellowish, 2 4'. nearly simple; m- 



vol. of 610 bristles much longer than the spikelets ; fruit rugous crosswise, some- 

 what triquetrous, blackish. Culm 2 3f. (T) Fields, gardens : common. 



3 S. virldis Beauv. Wild Timothy, (a) Spike cylindric, 1 3', compound, green , 



inyol. of 410 bristles much longer than the spikelets (b, c) ; fruit-pales striate leugth- 

 wise and dotted (under a lens). Culm 1 2f. (T) Cultivated grounds, N. | 



4 S. Germaiilca, Beanv. Millet. Bengal G. Spike flattened, oblong-cylindric, 



compound, 35' by 9" : rachis bristly ; invol. of 4 8 bristles, little longer than the 

 spikelets, yellowish ; >} pales dull-rugous. Culm 3 4f. (T) Fields. 



5 S. Itallca K. Spicate pan. 618' long by 12' thick; invol. yellowish, of 2 or 3 



bristles 810 times longer than the spikelets and half-concealing them ; e pales 

 smooth, polished, shining. Culm 4 6f. (T) Swamps, S. 



6 S. corrugata Schul. Spicate pan. 36', cylindric. dense above ; bristles 1 to each 



spikelet and thrice as long; pales strongly corrugated. Fla., Ga. 

 t S. composita K. Spicate pan. loose, its lower clusters separated ; bristles 1 or 2 

 under each spkl. and 5 times longer ; 9 flower acute, smoothish. Fla. 



24. CENCHRUS L. BURR G. Fls. rucemed or 

 spicate. Involucre a burr (a) beset with spines, be- 

 coming hard and pungent in fruit, and enclosing, 

 several (1 3) spikelets (b). Glumes and flowers as in 

 Panicum, the sterile flowe 5 . Culms branched. Aug. 



C. tribiiloides L. Culms 1 2f, tufted, decumbent, spreading; Ivs. as short a- 

 tlieir open compressed sheaths; spikes several, 1 2' loujj ; burrs adhering by the ; r 

 rough spines to everything passing. Sandy shores, N. J. to 111., and N. (See Addenda ) 



25. PHALARIS, L. CANARY G. Spikelets l-(theoretically 3)-flow- 

 ;red. Gl. 2, subequal, carinate, longer than the two shining pales of the 

 ? fl., all awnless. Neutral rudiments at base of the $ fl. merely 2 single 

 pales or hairy pedicels (b, c). Grain coated. Handsome flat-leaved grasses. 

 1 P. arnndliiacea L. Ribbon G. A showy but not valuable grass, 2 5f; Iv8. 



lance-linear ; pan. contracted, douse, 3 6' long ; glumes (a) 2$", pointed ; rudiments 



