112 POACEAE 



1. Zizaniopsis miliacea (Michx. ) Doell & Aschers. Stems 1-4 ra. tall, from a long 

 and creeping rootstock : leaf-sheaths smooth and glabrous ; blades 3-10 dm. long, 1-3 

 cm. wide, usually smooth and glabrous : panicle 2.5-6 dm. long : staminate spikelets 7-8 

 mm. long, more or less awned : pistillate spikelets 5-6 mm. long, the awn 2-6 mm. long. 



In swamps, Georgia and Ohio to Florida and Texas. Summer. WATER MILLET. MARSH MILLET. 



46. * ZIZANIA L. 



Tall robust annual monoecious aquatic grasses, with broad flat leaf-blades and ample 

 terminal panicles. Spikelets of two kinds, articulated below the scales, 1 -flowered, each 

 with a more or less prominent cartilaginous ring at the base, narrow, the staminate readily 

 deciduous, on the more or less spreading lower branches, the pistillate tardily deciduous, on 

 the erect or appressed upper branches of the panicle. Scales 2, the first empty, the second 

 enclosing a flower but no palet : scales of the staminate spikelets membranous, concave, 

 acute or awn-pointed ; those of the pistillate spikelets linear, firmer, involute, the first 

 long-awned, longer than the awn-pointed second. Stamens 6. Styles nearly distinct. 

 Stigmas plumose with short hairs. 



1. Zizania aquatica L. Annual. Stems 1-3 m. tall : leaf-sheaths smooth and gla- 

 brous ; blades 1.5-8 dm. long, 5-25 mm. broad, usually rough: panicle 2-3 dm. long: 

 staminate spikelets 7-8 mm. long : pistillate spikelets 12-20 mm. long, the awn 2.5-5 cm. 

 long. 



In swamps and along creeks and rivers, New Brunswick to Manitoba, Florida. Louisiana and 

 Texas. Summer and Fall. INDIAN RICE. WILD RICE. REEDS. WATER OATS. MARSH RICE. 



47. ORYZA L. 



Swamp grasses, with flat leaf-blades and terminal narrow panicles, the branches of 

 which are slender, erect and somewhat flexuous. Spikelets much compressed, articulated 

 below the empty scales, 1 -flowered. Scales 4, the 2 outer empty, very small, scale-like or 

 bristle-form, the 2 inner compressed-keeled, somewhat rigid, the first a little the larger, 

 empty, awned or awnless, the keel often narrowly winged or muricate, the second scarcely 

 shorter, narrower, short -awned or awnless, the keel not winged, naked, enclosing a perfect 

 flower but no palet. Stamens 6. Styles short, scarcely united at the base. Stigmas 

 plumose with short hairs. 



1. Oryza sativa L. Stems 5-10 dm. tall or more, simple : leaf-blades usually 

 rough * panicle 1-3 dm. long, its branches erect : spikelets 8-10 mm. long, oblong, hispid, 

 sometimes awned. 



In ditches and water, Virginia to Florida and Texas. Extensively cultivated. Native of tropical 

 Asia. Summer and fall. RICE. RICE GRASS. CUT GRASS. 



48. HOMALOCENCHRUS Mieg. 



Grasses of wet situations, with flat leaf-blades and usually open, rarely contracted, ter- 

 minal panicles, the branches of which are slender. Spikelets often with a cartilaginous 

 ring at the base, articulated below the scales, compressed, 1 -flowered. Scales 2, compressed- 

 keeled, somewhat rigid, awnless, the first scale empty, usually ciliate on the keel, broader 

 than the second which encloses a perfect flower but no palet. Stamens 1-6. Styles short 

 or slender, distinct. Stigmas plumose with branched hairs. [Leersia Sw., not Hedw.] 



Spikelets oblong to elliptic, their width less than % their length. 



Spikelets glabrous, 2 mm. long or less : stamen I : stems densely tufted, erect. 1. H. monandnts. 



Spikelets aculeate on the keels, hispidulous on the surface, 2.5 mm. long or more : 



stamens 2 or more : stems decumbent at the base. 

 Panicle-branches singly disposed, few. usually less than 8. 



Panicle-branches elongated, each with a long naked base ; stamens 2. 2. H. Virginicus. 



Panicle-branches short, spikelet-bearing to the base ; stamens 6. 3. //. hexandrus. 



Panicle-branches, at least the lower ones, in whorls or approximately in pairs, 



numerous, usually exceeding 15. 4. H. oryzaides. 



Spikelets broadly oval to nearly orbicular, their width more than % their length. 5. H. lenticularis. 



1. HomalocenchniB monandnis (Sw. ) Kuntze. Stems densely tufted, 4-6 dm. tall : 

 leaf-sheaths smooth and glabrous ; blades erect, 4-15 cm. long, 2-5 mm. wide, roughish : 

 panicle 7-13 cm. long, its branches ascending, slender, 3-4 cm. long : spikelets 1.75-2 mm. 

 long, about 1 mm. broad, smooth and glabrous : stamen 1. 



In dry soil, extreme southern parts of Florida and Texas. Also in tropical America. Spring. 



