OKTZOPSIS. 149 



Lakes, from Illinois and Micliigan northwestward. 

 Flowers in August. 



10. Calamageotis, Arenaria (Beach Grass, 

 Sea Sand, Reed, Mat Grass). 



SPECiriC CHAKACTER. 



Culm Stout and rigid (2 to 3 ft. high) from firm 

 running rootstocks ; panicle contracted into a dense 

 cylindrical spike (5 to 9 in. long) ; hairs only one 

 third of the length of the palet. 



This well knx)wn grass is found on sandy beaches, 

 from New Jersey to Maine and northward on the 

 Great Lakes. Its thick, strong, creeping, perennial 

 joots, with many tubers the size of a pea, prevent 

 the drifting of the sand from the action of the winds 

 and waves, thus forming a barrier against the en- 

 croachment of the ocean. This seems to be the chief 

 utility of the plant as it serves this purpose the 

 world over. 



14 ORYZOPSIS — Mich. Mountain Rice. 



GENERIC CHARACTER. 



Spikelets 1 -flowered, nearly terete. Glumes her- 

 Ibaceous or thin membranaceous ; several nerved J 

 nearly equal ; commonly, rather longer than the 

 oblong flowers, which is deciduous at maturity, and 

 with a very short, obtuse, callus or scar-like base. 

 Lower palet coriaceous, at length involute so as 

 closely to enclose the upper (of the same length) and 

 the oblong grain. A simple, untwisted and deciduous 

 awn, jointed on its apex. Stamens 3 ; Sc[uamul8e 2 



