I 



Thk (tHASSKS OK Tknnkhskk. 59 



ally, in terminal i)anicles; rachilla articulated below the empty 

 glumes, (ilumes three, the first two small, empty, the third com- 

 pressed keeled, somewhat rigid, usually awned. Palea one-nerved, 

 narrow, about the length of the glume. Stamens six. Grain 

 oblong obtuse, closely enveloped by the fruiting glume. Aquatic 

 grasses with flat leaves and terminal panicles. 



wSpecies five or six, in the tropics of both hemispheres. 



I. Oryza sativa Linn. Rice. 



This well-known })lant furnishes food to a greater number of 

 people than any other cereal. It is known to have been culti- 

 vated in eastern countries for more than 4500 years. It has been 

 grown in some of the Southern States — notably South Carolina 

 and Louisiana — for many years, and a variety known as upland 

 rice is grown to some extent in the western part of Tennessee. 

 There are many varieties, distinguished by the color or size of 

 the fruit and absence or presence of awns. 



15. LEERSIA Swartz. Nov. Gen. et Sp. 21 (1788). 



Spikelets one-llowered, hermaphrodite, strongly flattened later- 

 ally, articulated with the pedicels. Empty glumes none. Flower- 

 ing glume chartaceous, bristly ciliate along the keel, awnless. 

 Palea similar in texture and about as long as the flowering glume, 

 but much narrower. Perennials with rough leaves and open 

 paniculate inflorescence. 



Species five or six, throughout the tropical and temperate re- 

 gions of the world. Tennessee species three. 



KEY TO THE SPECIES. 



I. Spikelets pale green, less than 2 lines long . L. Viroinica. 



1. Spikelets straw-colored, more than 2 lines long 2 



2. Spikelets somewhat spreading, less than a line wide . . . 



L. ORVZOIDES. 



2. Spikelets closely imbricate, i^j lines broad. L. lenticularis. 



I. Leersia Virginica Willd. White-grass. 



Plate XVII. Figure 68. 



A slender, erect or ascending, usually much-branched leafy 

 grass, two to four feet long, from short, scaly root- stocks. Nodes 

 pubescent, with reflexed hairs. Sheaths retrorsely scabrous; ligule 

 membranous, very short; leaf-blade linear or narrowly-lanceolate, 

 two to five inches long and one to four lines wide, scabrous on 

 both surfaces, and very minutely and sharply scabrous on the mar- 

 gins. Panicle three to five inches long, simple, composed of a few 

 more or less spreading one-sided racemes one to three inches long. 

 Spikelets one and one-half to two lines long, strongly appressed to 

 the branches and closely imbricated; glume very abruptly short- 

 pointed, ciliate on the curved keel, and with a few very short, stiff 

 hairs on the sides, or nearly smooth; palea similar to the glume, 

 but narrower, and with nearlv a straight keel. 



