GENERA. OF GRASSES OF THE UNITED STATES. 47 



belong two common annual weeds, Eragrostis cilianensis (All.) Link 

 (E. mcgastachya (Koel.) Link, E. major Host), a disagreeable smell- 

 ing grass (fig. 15) with rather compact panicles of large spikelets 

 (3 mm. wide), the keels of the lemmas glandular dotted, and E. caro- 

 liniana (Spreng.) Scribn., with open panicles of small spikelets 

 (about 1.5 mm. wide). 



Eragrostis pectinacea (Michx.) Nees (fig. 16) is a perennial with 

 handsome purple open'panicles, which at maturity separate from the 

 plant and tumble before the wind. 



Eragrostis Jiypnoides (Lam.) B. S. P. is a spreading dioecious 

 annual found on sandy river banks. Eragrostis ciliaris (L.) Link 

 (fig. 17) and E. amabilis (L.) Wight and Am. (E. plwmosa Link) 

 are tropical annuals that extend into the Gulf States. They have 

 conspicuously ciliate paleas and disarticulating rachilla. A common 

 perennial species in sandy soil from Kansas to Texas is E. secundiflora 

 Presl (E. oxylepis Torr.) with contracted purple panicles, the rachilla 

 disarticulating and the florets falling separately. 



In general, the species of Eragrostis have little forage value. 



11. CATABROSA Beauv. 



Spikelets mostly 2-flowered, the florets somewhat distant, the 

 rachilla disarticulating above the glumes and between the florets; 

 glumes unequal, shorter than the lower floret, flat, nerveless, irregu- 

 larly toothed at the broad truncate apex ; lemmas broad, prominently 

 3-nerved, the nerves parallel, the broad apex scarious; palea about 

 as long as the lemma, broad, scarious at the apex. 



Aquatic perennials, with creeping bases, flat soft blades, and open 

 panicles. Species seven, in northern Eurasia and North America, 

 extending south to New Brunswick and Colorado ; one in Chile. 



Type species : Aira aquatica L. 



Gatabrosa Beauv., Ess. Agrost. 97, pi. 19, f. 8. 1812. The species illustrated 

 is C. aquaticd. Another name mentioned is a nomen nudum. 



Catabrosa aquatica (L.) Beauv. (fig. 18) is found in mountain 

 meadows around springs and watercourses. It is an unimportant 

 forage grass. 



12. MOLINIA Schrank. 



Spikelets 2 to 4 flowered, the florets distant, the rachilla disarticu- 

 lating above the glumes, slender, prolonged beyond the upper floret, 

 and bearing a rudimentary floret; glumes somewhat unequal, acute, 

 shorter than the first lemma, 1-nerved ; lemmas membranaceous, nar- 

 rowed to an obtuse point, 3-nerved; palea bowed out below, equaling 

 or slightly exceeding the lemma. 



