ORYZOPSIS. 149 



Lakes, from Illinois and Michigan northwestward. 

 Flowers in August. 



10. Calamaorotis, Arenaria (Beach Grass, 

 Sea Sand, Keed, Mat Grass). 



SPECIFIC CHARACTER. 



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 known grass is found on sandy beaches, 

 from New Jersey to Maine and northward on the 

 Great Lakes. Its thick, strong, creeping, perennial 

 roots, ^vith 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. Moui^ttaix Rice. 



GENERIC CHARACTER. 



Spikelets 1 -flowered, nearly terete. Glumes her- 

 baceous or thin membranaceous ; several nerved ; 

 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 simj)le, untwisted and deciduous 

 awn, jointed on its apex. Stamens 3 ; Squamulae 2 



