GRAMINACE^. 419 



branous ; albumen farinaceous. Stem (culm) cylindric, usually 

 hollow and closed at the jomts, sometimes solid. Leaves nar- 

 row and undivided, alternate, with a split sheath, and a mem- 

 branous expansion {ligule) at the junction of the stalk and blade. 

 Flowers green, in small spikelets, arranged in a spiked racemed 

 or panicled manner. 



I. Oryze-e. Spikelets either one-Jlowered, with the glumes mostly 

 abortive, or 2 — 3-Jlowered, one or both of the lower flowers with a single 

 palea and neutral, the terminal one fertile. Paleoc somewhat coriaceous. 

 Stamens 1 — 6. 



1. LEERSIA. Sfwar/^.— White Grass. 

 (Named in honor of J. D. Leers, a German botanist.) 



Spikelets 1 -flowered, compressed. Glumes none. Palese 2, 

 compressed-carinate, awnless ; lower one much broader. Sta- 

 mens 3 — 6, rarely solitary. — Panicle simple or branched. 



1. L. Viginica Willd. : panicle simple, the lower branches spreading ; 

 flowers appressed, monandrous, sparingly ciliate on the keel. 



Wet woods. Can. to Car. W. to Ohio. Aug. Tl. — Culm 2 — 4 feet high, 

 slender, branched, geniculate, erect or decumbent. Leaves linear-lanceolate, 

 rough. Panicle terminal, at length much exserteA; branches few and soUtary. 



Virginian White-grass. 



2. L. orT/zoides Swartz ; panicle branched, diffuse, often sheathed at base ; 

 spikelets rather spreading ; flowers triandrous ; paleae strongly ciliate on the 

 keel. 



Ditches and swamps. Throughout the U. S. Aug. Sept. % . — Root creep- 

 ing. Culm 3 — 5 feet high, geniculate, rough. Leaves lanceolate, acuminate, 

 very rough, with hooked prickles. Paraic/e with many widely spreading and 

 flexuous branches. A worthless grass. Cut-grass. 



2. ZIZANIA. Linn.—W\\di Rice. 

 (A Greek name, supposed to have been originally applied to Lolium perenne.) 



Monoecious. Spikelets one-flowered. Sterile. Fl. Glumes 

 none, or only rudimentary. Paleae 2, herbaceous, concave, 

 nearly equal, awnless. Stamens 6. Perfect. Fl. Glumes none. 

 Palese 2, herbaceous ; lower one longer, oblong, keeled, termi- 

 nating in a straight awn. Styles 2, short. — Panicle large, ter- 

 minal. 



1. Z. aqiiatica Linn.: panicle • pyramidal ; lower branches spreading, 

 sterile ; upper branches nearly erect, fertile ; spikelets on clavate pedicels ; 

 awns long ; caryopsis slender, linear. Z. clavulosa Mich. 



Swamps and overflowed banks. Can. to Flor. W. to Miss. Aug. % — 

 Culm 4--8 feet high, stout, terete, smooth. Leaves very long, broad-linear. 

 Panicle terminal, a foot or more long, with verticillate branches. 



WiU Rice. Water Oats. 



