618 CLXI. GRAMINE^:. ATHEROPOION. 



closely imbricate, smooth; upper glume 5-veined; Jr. dark brown. Common 

 about houses, foot-paths, &c., Mid. and W. States. Aug. 



47. CYNODON. Rich. 



Gr. /fucov, a dog, oSos, tooth ; alluding to the singular, one-sided spikelets. 



Spikes digitate or fasciculate ; spikelets unilateral, in a single row ; 

 glumes membranaceous, shorter than the flowers, persistent ; 9 upper 

 palea bifid-toothed ; rudiment minute, pedicellate, in a groove of the 

 upper palea ; scales truncate. 



C. DACTYLON. Pers. (Digitaria. Ell. Panicum. Linn.") Bermuda Grass. 



Rt. creeping extensively ; st. creeping, stoloniferous at base, 1 2f long ; 

 Ivs. hairy on the margin and towards the base, narrow-linear ; sheaths hairy ; 

 spikes 4 5, digitate, spreading, 2 3' long, serrated with the uneven spikelets ; 



flumes scabrous on the keel, lanceolate, acute; pakce subequal, the lower 

 roader, enfolding the upper. 7J. A vigorous creeper, in sands and hard soils, 

 Penn. to Ga. 



48. GYMNOPOGON. Palis. 



Gr. yu/xvoj, naked, 7rwywi>, beard ; alluding to the long awn of the palea. 



Spikes setaceous, paniculate ; glumes 2, keeled, subequal, the 



lower with a straight awn from a little below the tip j rudiment aris- 



tiform. 



G. RACEMOSUM. Palis. (Anthropogon lepturoides. Nutt.} 



St. ascending, 18 24' high, with short internodes ; Ivs. ovate-lanceolate, 



1 2' by 48", glabrous, flat, spreading, in 2 rows ; sheaths hairy at the throat; 



slip, obsolete ; panicle large, pyramidal, branches simple, rigid, verticillate, 



spreading, 3 5' long; spikelets sessile, appressed; glumes linear, pungent; 



lower palea with an awn at its back 3 4 times its length, upper bifid. 7J. 



Sandy fields, N. J. to Ga. Aug. 



49. SPARTlNA. 



Spikelets imbricated in a double row in unilateral, paniculate 

 spikes ; glumes 2, unequal, compressed ; palese 2, subequal, com- 

 pressed, awnless ; style long, bifid. 



1. S. CYNOSUROIDES. Willd. (Limnetis. Pers.) 



St. slender, smooth, 3 5f high ; Ivs. 2 3f long, sublinear, convolute and 

 filiform at the end ; sheaths striate, glabrous ; panicle loose, slender, composed 

 of 20 or more alternate, one-sided, pedunculate spikes 2 3' long; -spikelets 

 arranged on 2 sides of a triangular rachis; glumes acuminate, one of them 

 with a short awn ; palea white and awnless. % Marshes, Free States and 

 Can. A coarse, sedge-like grass. Aug. 



2. S. JUNCEA. Willd. (Limnetis. Pers.} 



Rt. creeping extensively ; st. erect, rigid, round, smooth, 1 2f high ; Ivs. 

 convolute at the edges, spreading, in 2 rows ; spikes 3 5 ; ped. smooth ; rachis 

 compressed; lower glume 3 times as long as the upper; palea obtuse, lower one 

 shorter; sty. 2. 7J. Marshes and river banks, Free States and Can. Jl., Aug. 



3. S. GLABRA. Muhl. 



St. smooth, succulent, terete, 3 5f high; Ivs. concave, erect, about 2f 

 long, ' wide at base, tapering to a long acumination ; spikes 10 15, erect and 

 appressed, alternate and sessile upon a triangular rachis ; spikelets in a dense, 

 double row. QJ. Marshes, Indiana! Aug., Sept. 



50. ATHEROPOGON. Muhl. 



Gr. a$T)(>, chaff, Trwyajv, beard; a characteristic term. 



Spikes in a thin, simple raceme ; glumes 2, membranaceous, 2- 

 flowered, lower one setiform ; paleae 2, lower one 3-toothed or 3- 

 bristled, upper bifid ; abortive flower pedicellate, paleae 2 3-bristled. 



