394 



ORDER 155. GKAMINEJG. 



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



one-sided, f 1' long, alternate; glumes hispid, pointed; the fls. somewhat pointed, 

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



3 O. hirtellus R. & S. Decumbent, branched, ciliate ; Ivs. lanceolate, 12' 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. SETARIA, 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 as in Panicum. July, Aug. 



Bristles rough backward, in pairs, short No. 1 



Bristles rough upward (a) 



a 410 in each involucre Nos. 24 



a 13 in each involucre Nos. 57 



1 S. ver tit-ill at a Beauv. Spicate pan. 23', composed 

 of short divided branchlets seeming in many verticils ; 

 bristles little longer than the spikelets; fruit-pales 

 rough-punctate. Culin 2f. N. fing. to Car., and W. 



2 S. glauca Beauv. Bottle G. Spike cylindric, yellowish, 24', nearly simple-; in- 



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

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



3 S. viridis Beauv. Wild Timothy, (a) Spike cylindric, 13', compound, green ; 



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

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



4 S. Germaiiica Beauv. Millet. Bengal G. Spike flattened, oblong-cylindric, 



compound, 35' by 9" ; rachis bristly ; invol. of 48 bristles, little longer than the 

 spikelets, yellowish ; s pales dull-rugous. Culm 3 4f. (J) Fields. 



5 S. Italica 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 ; c 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. 



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



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



24. CENCHRUS L. BURR G. Fls. racemed 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 flower S . Culms branched. Aug. 



C. tribuloides L. Culms 1 2f, tufted, decumbent, spreading; Ivs. as short as 

 their open compressed sheaths ; spikes several, 12' long ; burrs adhering by their 

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



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

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

 fl., all awuless. Neutral rudiments at base of the 2 fl. merely 2 single 



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



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

 lance-linear ; pan. contracted, dense, 3 6' long ; glume? (a) 2J", pointed ; rudiments 



