GRAM1M I'.. (GRASS FAMILY.) L>o7 



18. ETJSTACHYS, Desv. 



Chiefly tropical grasses, with compressed culms and sheaths, distichous flat or 

 folded obtuse leaves, and digitate rarely single spikes. Spikelets 2-3-flowered, 

 imbricated or crowded in 2 rows on one Bide of the triangular rachis ; the lowest 

 flower perfect and sessile, the upper ones Btaminate or neutral, and stalked. 

 Glumes 2, membranaceous, persistent, the upper (exterior) one short-awned. 

 Palesa coriaceous, the lower one boat-shaped, mucronate-awned under the apex, 

 the upper (mostly wanting in the sterile flowers) unawned. Stamens 3. Grain 

 free. 



1- E. petrsea, Desv. Culms (l°-2°high) clustered, erect; leaves glau- 

 cous; spikes 3-5; spikelets 2-flowered ; glumes hispid, the upper oblong, 

 deeply emarginate ; lower palea dark brown, hairy on the keel ami margins, 

 bearded at the base; sterile flower neutral, club-shaped, awnless. — Damp soil 

 along the coast, Florida to North Carolina. .May- Aug. y. — Leaves 3' -5' 

 long. Spikes erect. Spikelets roundish. 



2. E. glauca, n. sp. Culms stout (3° - 5° high), and, like the broad 

 (6" -8" long) leaves, smooth and glaucous; spikes about 20; spikelets roundish, 

 2-flowered ; glumes hispid, the upper lanceolate, entire ; palea- dark brown, 

 smooth ; upper flower obovate, short-awned. — Brackish m irshes, West Florida, 

 Aug. and Sept. (l) — Culms h' wide at the base. Leaves lj°- 2° long. 



3. E. Floridana, n. sp. Culms slender (2° high) ; leaves (2' -4' long) 

 glaucous ; spikes single or by pairs ; spikelets light brown, 3-flowercd, the mid- 

 dle flower staminate ; glumes smoothish, truncate, oblong ; lower palea of the 

 perfect flower hairy on the keel and margins, distinctly awned ; sterile flowers 

 obovate, smooth, the lower one short-awned. — Dry pine barrens, Middle Flor- 

 ida. July- Sept. 1|. — Spikelets larger than in the two preceding. 



19. CYNODON, Richard. Bermuda-Grass. 



Diffusely creeping grasses, with short and erect flowering stems, and flat 

 leaves. Spikes digitate, 1 -sided. Spikelets crowded, awnless, 2-flowered; the 

 lower flower perfect, the upper an awn-like pedicel. Glumes 2, membranaceous, 

 nearly equal. Palese 2, membranaceous, the lower one larger and keeled. Sta- 

 mens 3. Grain free. 



J. 1. C. Dactylon, Pcrs. Spikes 3-5, filiform, purple; glumes rough, 

 keeled ; palese longer than the glumes, the lower one boat-shaped, and hairy 

 on the keel ; anthers and stigmas purple. (Digitaria Dactylon, Ell.) — Waste 

 places. Introduced. — Culms perennial. Leaves 2' -4' long. Spikes l'-2' 

 long, filiform. 



20. CTENIUM, Panz. 



Flat-leaved grasses, with the erect culms terminated by a single falcate spike. 



Spikelets 4 - 5-flowered, crowded in two rows on the lower side of the flattened 



rachis ; the two lower sterile, of 1 -2 palea which are awncd under the apex, 



and similar to the third perfect one; the upper ones (1-2) abortive and awn- 



47* 



