GRAMINE^. (grass FAMILY.) 557 



18. EUSTA.CHYS, Desv. 



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

 folded obtuse leaves, and digitate rarely single spiiies. Spilielets 2 - 3-flowered, 

 imbricated or crowded in 2 rows on one side of the triangular rachia ; the lowest 

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

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

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

 the upper (mostly wanting in the sterile flowers) unawncd. 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 palca dark brown, hairy on the keel and margins, 

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

 along the coast, Florida to North Carolina. May -Aug. 11 — 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 ; palese dark brown, 

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

 Aug. and Sept. (l) — Culms J' wide at the base. Leaves 1^° - 2° long. 



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

 glaucous ; spikes single or by pairs ; spikelets light brown, 3-flowered, 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. IJ. — Spikelets larger than in the two preceding. 



19. CTNODON, Richard. Bermuda-Geass. 



Difl^usely 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. Palcse 2, membranaceous, the lower one larger and keeled. Sta- 

 mens 3. Grain free. 



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

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

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

 places. Introduced. — Culms perennial. Leaves 2' -4' long. Spikes I' -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 ,pale» which are awned under the apex, 

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



47* 



