44 ]Mr. Woods o)i the Genera of European Grasses. 



by many botanists. It dilters from both in its one-sided head of flowers, and 

 I readily foUow Link in making of it a distinct genus under the name of 

 OreocJdoa. Sclerocliloa durii has nothing in common with Sesleriu eitlier in 

 character or habit, nor can I understand what induced Linnaeus to join it 

 with Ci/nosiirus. Its nearest affinity is that jjointed out by Palisot de lîeau- 

 vois with Sclerochlna procionhens, but this can by no means be separated 

 from S.mar'ithna and the other G///r«-/a' of Smith. Sclerochloa thus formed 

 i<;, I think, a natural genus, though it must he confessed that S. dura is very 

 liitferent from the more delicate species, and esjiccially from the Fesfuca ex- 

 pansa of Kunth, wliicli yet seems better placed in this than in any other 

 admitted genus; but the dichotomous inflorescence, thickened flower-stalks, 

 and connate gliunes, might, if it had companions, make it the type of a sepa- 

 rate one ; Trinius accordingly has named it Splienopus. 



The purple stain noticed in Poa between the thicker part of the palea and 

 its scariose transparent margin occurs also in Sclerochloa, and in some species 

 of Fesfuca and of Arena. I suspect it to have something to do with tlie struc- 

 ture of the parts, though I cannot point out the relation. 



I place with Sclerochloa two plants, not generally admitted into the genus, 

 Poa rimda and Tr'itkum loUaceum. In the former, the outer palea is totailv 

 without ribs and terminates in a small mucro, but its hal>it and one-sided 

 panicle agree very well with that of the genus. The latter al)solutely differs 

 in nothing from the rest but in its nearly sessile florets ; and the branched 

 rachis and one-sided spicnlae keep it very distinct from TriUcam. Poa iitfo- 

 ral'is, auct., is nearly allied in hal)it to Sclerochloa : but the acute form and 

 decided mncro of the outer palea obliges me to join it to Fesfuca. 



Glvceria was established by Brown on Fesfuca Jlu'if.ans alone. Smith 

 added several species from Poa. Kuiith transferred these to Fesfuca, preser- 

 ving from among them only G. acjuafica in addition to the original species. 

 The two plants differ considerably in habit, and the latter has a panicle equal 

 all round, wliile in the former it is one-sided ; yet the structure of the flowers 

 is so similar that I cannot separate them. 



Era^rosfis. Every botanist easily distinguishes this by its habit from Poa. 

 I think the nature of the outer palea, whose texture is equal throughout, wiiile 

 in Poa it is invariably firm at the hase, and terminates in a scariose extremity, 



