618 CLXI. GRAMINEiE. Atheropogon. 



closely imbricate, smooth ; tipper glume 5- veined ; fr. dark brown. — Common 

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



47. CYNODON. Rich. 



Gr. KVUiVj a dog, oSoif 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; 

 glumes scabrous on the keel, lanceolate, acute; palece subequal, the lower 

 broader, enfolding the upper. — % A vigorous creeper, in sands and hard soils, 

 Penn. to Ga. 



48. GYMNOPOGON. Palis. 

 Gr. yvjivos, naked, ircoycov, 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 ; rudiment aris- 



tiform. 



G. RACEMosuM. Palis. (Anthropogon lepturoides. Nutt.) 



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



1—2' by 4 — 8", 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. — 1\ 



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



49. SPARTINA. 

 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 ; palece 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 ; ^^aZe^; obtuse, lower one 

 shorter; sty. 2.— Tf-^Marshes and river banks, Free States and Can. J]., 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. — % Marshes, Indiana ! Aug., Sept. 



50. ATHEROPOGON. Muhl. 



Gr. aSrrjp, chaff, Trwywr, beard; a characteristic term. 



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

 flowered, lower one setiform ; $ pale83 2, lower one 3-toothed or 3- 

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



