178 Trans. Acad. Sci. of St. Louis. 



imperfect flowers. I therefore propose the following new 

 genus : — 



NEERAGK08TIS. 



Prostrate, creeping and rooting, dioecious or monoecious 

 grasses, with short flat leaves, and contracted paniculate in- 

 florescence. Staminate and pistillate spikelets unlike; stylif- 

 erous in subcapitate panicles, the spikelets closel}'^ flowered, 

 the scales very acute, appressed; staminate in looser, elon- 

 gated, acute panicles, usually larger and longer, the flowering 

 scales longer and less acute, spreading. Spikelets many-flow- 

 ered, more or less flattened ; the two lower scales empty, 

 unequal, shorter than the flowering scales, keeled, 1-nerved, 

 or the second 3-nerved; flowering scales membranous, keeled, 

 3-nerved; palets shorter than the scales, prominently 

 2-nerved or 2-keeled, usually persisting on the rachilla 

 after the fruiting scale has fallen ; stamens 2 or 3 ; styles 

 distinct, short; stigmas plumose; grain free, loosely in- 

 closed in the scale and palet. — Two known species, both of 

 the New World, much alike in habit, but differing consider- 

 ably in character, both annual in North America, but prob- 

 ably perennial in tropical regions. Type species, Poa Wei- 

 geltiana Eeichenb. Mem. Acad. Sci. Peterbs. Ser. vi. 1: 40 

 (1831), collected in Surinam, — to which I have referred Poa 

 capitata Nutt., of Arkansas. 



Name composed of ]SFeo, new, and Eragrostis, — New 

 Eragrostis. 



ANALYSIS OF SPECIES. 



DioeciouM. Flowering scales longer, pubescent: sheaths densely pilose 



pubescent. 1. N. Weigeltiana. 



Mo7ioecious. Flowering scales shorter, smooth ; sheaths smooth or nearly 



BO. 2. N. HYPNOIDE8. 



1. Neeragrostis Weigeltiana (Eeichenb.) B. F. Bush. 

 Poa Weigeltiana Reichenb. Mem. Acad. Sci. Petersb. VI. 1 : 40 (1831). 

 Poa capitata Nutt. Traus. Am. Phil. Soc. N. S. 5 : 146 (1837). 

 Eragrostis capitata (Nutt.) Nash ia Britton, Man. Nor. States and Can. 

 Append. 1042 (1901). 



