96 



GRASSES OF IOWA. 



TRIBE VI.— ORYZE^E. 



« 



Spikelets usually much compressed laterally, i-flowered, staminate, 

 pistillate, or hermaphrodite; empty glumes 2 or none, the flower being 



subtended by the floral glume and 

 palea alone, the latter i -nerved 

 and regarded by some as a sec- 

 ond glume; stamens frequently 

 b; axis of the inflorescence not 

 articulated. 



A small tribe of about forty 

 species, divided among sixteen 

 genera, mostly confined to tropi- 

 cal America. The best known 

 representative in Iowa is rice- 

 cut grass (Leersia), of which there are three species, and another repre- 

 sentative, wild rice (Zizania), but the most important member is the 

 rice (Oryza sativa) , of the Old World, because of its extensive use as 

 a cereal. 



Fig. 



Spikelet of Leersia oryzoides. 



KEY TO THE GENERA OF THE ORYZEAE. 



Spikelets unisexual, plants monoecious Zizania. 1 



Spikelets perfect, strongly compressed Leersia. s 



1. ZIZANIA. 



Zizania L. Sp. PI. S91. 1753. Endlicher. Gen. PI. 78. Bentham and 

 Hooker. Gen. PL 3: 1115. Hackel in Engler and Prantl. Nat. Pflanz. Fam. 

 II. 2: 40. Scribner. Bull. U. S. Dept. Agrl. Div. Agros. 20: f. 33. 



Hydropyrum Link. Hort. Berol. 1: 252. 



Flowers monoecious; the staminate and pistillate both in i -flow- 

 ered spikelets in the same panicle. Glumes 2, subtended by a small 

 cartilaginous ring, herbaceo-membranaceous, convex, awnless in the 

 sterile, the lower one tipped w T ith a straight awn in the fertile spikelets. 

 Palet none. Stamens 6. Stigmas pencil-form. Large, often reed-like, 

 water grasses. Spikelets jointed upon the club-shaped pedicels, very 

 deciduous. (Adopted from the Greek word for the ancient name of 

 some wild grain.) 



A monotypic genus in North America, from Maine to Florida and 

 Texas; Arkansas, Nebraska, Iowa, Dakota, Minnesota, Wisconsin, New 

 Foundland and Ontario. 



