GRAMINE.E. (GRASS FAMILY.) 419 



36. EATONIA, Raf. 



Perennial, slender grasses, with simple and tufted stems, and often sparsely 

 downy sheaths, flat lower leaves, and small greenish (or purplish) spikelets. 



1. E. Obtusata, Gray. Panicle dense and contracted, somewhat inter- 

 rupted, rarely slender : spikelets crowded on the short erect branches : upper 

 glume rounded-obovate, truncate-obtuse, rough on the back. Manual, 626. 

 Across the continent, occurring most abundantly in the southern part of our 

 range. 



37. CATABROSA, Beauv. 



Glabrous creeping aquatics, with flat leaves, elongated membranous ligules, 

 and diffusely branched panicles with semi-verticillate branches : flowers jointed 

 at base and deciduous. 



1. C. aquatica, Beauv. Stems 4 inches to 2 feet high, rather stout, as- 

 cending : leaves 2 to 6 inches long, 2 to 4 lines wide, scabrous on the margin : 

 panicle uniform, branchlets numerous, divided : flowers light-brown : glumes 

 purplish. In the Rocky Mountains. 



38. ERAGROSTIS, Beauv. 



Stems often branching : leaves linear, frequently involute, and the ligule or 

 throat of the sheath bearded with long villous hairs. 1 



1. E. Purshii, Schrad. Sparingly branched at the decumbent base, then 

 erect, ^ to 2 feet high : leaves narrow, flat and soft : panicle elongated, the 

 branches widely spreading, very loose ; spikelets 5 to 1 8-flowered, oblong-lan- 

 ceolate, at length linear, mostly much shorter than their capillary pedicels : 

 glumes ovate and acute, the flowering glume 3-nerved. From Nevada, 

 Colorado, and New Mexico eastward to New Jersey. 



39. ME LIC A, L. MELIC GRASS. 



Perennials with soft and flat leaves : panicle simple or sparingly branched ; 

 the rather large spikelets racemose-one-sided. Ours belong to EUMELICA, in 

 which the spikelets are 4 to 8 lines long, with 2 to 8 perfect florets; flowering 

 glume apparently many-nerved below (at least when dry), with a broad scari- 

 ous margin above. Scribner, Proc. Philad. Acad., 1885, p. 40. 

 # Stems not bulbous at base. 



1. M. Porteri, Scribner. Panicle narrow, the slender branches erect, or 

 the lower slightly divergent, the pedicels flexuose or recurved, densely pubes- 

 cent : empty glumes very unequal and decidedly shorter than the 3 to 5-flow- 

 ered spikelets. Rusby's Arizona Plants. M. miitica, var. parviflora, Porter. 



1 E. poceoides, Beauv. , var. megastachya, Gray, is a very common introduced species, and 

 may be recognized by its large, short-pedieelled, densely-flowered (10 to 50), flat, lead-colored 

 spikelets, which become linear and whitish when old, forming a narrow crowded panicle ; 

 its diffusely spreading habit, and its mostly glabrous sheaths. It is said to emit an unpleas- 

 ant odor. 



E. pilosa, Beauv., is another introduced species, like E. Purshii in general habic ; but may 

 be distinguished by its spikeleta about equalling their pedicels, its obtuse glumes, and the 

 1 -nerved flowering glume. 



