GRAMINACE.E. 435 



feet, and surrounded by a tuft of hairs. Paleae very unequal ; 

 the lower one elongated, acuminate ; the upper 2 -keeled. — 

 Panicle terminal, very large. 



P. communis Trin.: panicle loose, 1 -sided; spikelets 3 — 5-flowered. 

 Arundo Phragmitcs Linn. 



Margins of swamps and ponds. Can. to Geor. W. to Miss. Aug. %.. — Culm 

 9 — 12 feet high, very leafy, with numerous joints. Leaves 1 — 2 feet long, linear- 

 lanceolate, flat, glaucous, rough on the margin. Panicle terminal, very large, 

 loose, somewhat nodding. The largest grass in the Northern States ; and at a 

 distance somewhat resembling Broom-corn. Common Reed-grass. 



VII. Chlore^. Spikelets arranged in unilateral digitate or pan- 

 iculate (rarely solitary) spikes, 1- many-flowered; wpper flowers imper- 

 fect. Glumes and palecc 2, membranaceously herbaceous ; the latter 

 often awned. Racliis not articulated. 



26. CYNODON. /?/cA.— Dog's-tooth Grass. 

 (From the Greek Kvoiv, a dog, and o6ovi, a tooth.) 



Spikelets filiform, unilateral, with one perfect flower and one 

 abortive rudiment. Glumes membranaceous, persistent, shorter 

 than the flower and only embracing it at the base. Fertile 

 flower with the upper palea bifid-toothed. Rudiment minute, 

 pedicellate. Caryopsis loose, not furrowed. — Spikes digitate or 

 racemose. 



C. Dadylon Pers. : cplm creeping ; spikes digitate, 3 — 5, spreading ; 

 glume with the keel scabrous ; paleae smooth, longer than the glume, the 

 lower one with a bristle at the base. Digitaria Dadylon Muhl. 



Sandy soils. Penn. to Geor. July, Aug. %. — Culm a foot or more long, 

 prostrate. Leaves narrow, somewhat distichous, hairy on the margin and near 

 the base. Stigmas dark purple. Introduced. Creeping Dog's-tooth Grass. 



27. ELEUSINE. G^r^.— Dog's-tail Grass. 



(EXtvo-ij/ja was one of the names of Ceres, the goddess of harvests; probably 

 from Eleusis, where she was worshipped.) 



Spikelets sessile, 2 — 6 -flowered. Glumes unequal, shorter 

 than the flowers. Paleae unequal, awnless ; the lower keeled ; 

 upper shorter, channelled on the back. Caryopsis triangular- 

 ovoid, transversely rugose. — Spikes digitate, unilateral. 



E. Indica Gcert. : culm oblique, compressed ; leaves smooth ; spikes 2 — 4, 

 linear, straight j spikelets closely imbricate, lanceolate, about 5-flowered. 

 Cynosurus Indlcus Linn. 



Cultivated grounds, in farm-yards, &c. Throughout the U. S. July~Nov. 

 (!)• — Culm 9 — 18 inches long, compressed, branching from the base. Leaves 

 distichous, linear, somewhat pubescent. Spikes 1 — 6, but usually 2 — 4. Prob- 

 ably introduced. Dog's-tail Grass. Wire-grass. 



