142 GRASSES OF IOWA. 



Urachne Trin. Fundam. Agros. 109. 1820. 



Eriocoma Nutt. Gen. N. Am. PI. 1: 40. 



Fend/eria Steud. Syn. PI. Shun 1:419. (Fendler Collection 979.) 



Caryochloa Spreng. Syst. Cur. Post. 22: 30. 1827. 



Piptatkerum Beauv. Agros. 17. 1812. 



Piptochaetium Presl. Rel. Haenk. 1: 222. 1830. 



Nasse/la D. Desvx in Gay. F. Chili. 6: 263. 1845. 



Spikelets I -flowered, nearly terete. Lower glumes herbaceous or 

 thin membranaceous, several-nerved, nearly equal, commonly rather 

 longer than the oblong flower, which is deciduous at maturity, and with 

 a very short, obtuse callus or scar-like base. Flowering glume coriaceous, 

 at length involute so as closely to enclose the equal palet and the oblong 

 grain; a simple untwisted and deciduous awn jointed on its apex. 

 Stamens 3. Squamulae 2 or 3, conspicuous. Stigmas plumose. Peren- 

 nials, with rigid leaves and a narrow raceme or panicle. Spikelets green- 

 ish, rather large. (Name composed of two Greek words for rice and 

 likeness, from a fancied resemblance to that grain.) 



Bentham & Hooker give the number of species as 24; Hackel 15. 

 Found chiefly in the warmer temperate zones of both hemispheres; 

 Heller gives the number as 11, which includes Eriocoma. 



KEY TO THE SPECIES OF ORYZOPSIS. 



Flowering glume sparingly pubescent, awn about 20 mm. long. 



— O melanocarpa .^ 



Flowering glume densely silky-hirsute, awn about 5 mm. long. 



— O. cnspidata .- 



1. ORYZOPSIS MELANOCARPA. 



Oryzopsis melanocarpa Muhl. Gram. 79. 1817. Watson and Coulter. 

 Gray. Man. Bot. 642. 1890. (6th ed.) Beal. Grasses of N. A. 2: 225. 1896. 

 Nash in Britton and Brown. 111. Fl. 1:140 f.317. 1898. Scribner. Am. 

 Grasses. Bull. U. S. Dept. Agrl. Div. Agros. 7: 98. f. 92. 1900. (3d ed.) 

 Vasey Contr. U. S. Nat. Herb. 3: 56. 



