82 ME. G. BESTnAM ON GEAMINEiE. 



Spreng., Piptochatium, Presl, and Nassella, E. Desv., is entirely 

 American, with the typical character of the genus, and the rha- 

 chilla bearing a ring of hairs under tte flowering glume. 3. Erio- 

 coma, Nutt. {Fendleria, Steud.), differs from Euoryzopsis only in 

 tte long silky hairs clothing the fruiting glume. 



4. Milium, Linn., was formerly extended to several unawned 

 Panieese with only two empty glumes, but is now reduced to five 

 or six European or temperate Asiatic species, one of wMch is 

 also spread over North America, all removed from Panicaeese as 

 having the empty glumes persistent below the articulation. They 

 diifer from Oryzopsis chiefly in their obtuse absolutely unawned 

 flowering glume. 5. Aoiachnb, Benth., is a single dwarf tufted 

 dioecious grass from the higher mountains of Peru and Colombia. 

 The female individual, with only one spikelet terminal on the pe- 

 duncle, is fully described and figured in the last part of Hooker's 

 ' Icones.' The male plant, if correctly matched, of which I am 

 by no means certain, has a loose almost simple panicle with pre- 

 cisely the glumes of the female, but enclosing stamens only. In 

 the few specimens seen the leaves are much longer than iij the 

 numerous females from various localities, which makes me rather 

 doubt the specific identity of the two. 



6. MuEHLENBEEGiA, Schrcb,, has nearly sixty known species, 

 chiefly American, extending from the Andes of South America 

 over the northern continent generally, with a very few from 

 central or eastern Asia. They connect, in many respects, Stipa 

 with AgrosUs. In general they come very near in technical 

 character to the smaller-flowered Stipas, differing in the still 

 smaller spikelets with thinner though still closely appressed and 

 narrow fruiting glumes, and usually with a more or less hairy 

 rhachilla. Erom Agrostis and its immediate allies they may be 

 readily distinguished by this narrow appressed fruiting glume 

 with a terminal never dorsal awn ; a very few unawned species 

 are scarcely separable from JSpieampes, except by the shape of the 

 glume. There is a considerable variety in the inflorescence and 

 in the proportions of the glumes, but nothing definite enough to 

 establish good sections, although several separate genera have 

 been proposed. In the original M. diffusa, Schreb., and its im- 

 mediate allies, the panicle is usually long, narrow, and dense, 

 and the lower empty glumes are very minute ; whilst in Trinius's 

 proposed section Acroxis both the lower glumes or one only of 

 them are nearly as large as the flowering one ; but throughout the 



