10 Mr. Woods on the Genera of European Grasses. 



12. Rottboelliacece, 1 1 genera, 3 of which occur within my limits, Nardus, Psi- 



lurus, and Lepturiis. This latter genus includes the European species 

 of RottboelUa. 



13. Andropogonece, 26 genera. Imperata, Erianthus, and Andropogon are all 



with which I am concerned. The last-mentioned genus is made by 

 Kunth to include Sorghum of Smith. 



Of this distribution we may observe, that the structure of Lygeum is so 

 peculiar that we can hardly gain any thing by uniting it with others into a 

 particular tribe, and that Zea, although described as having an external neutral 

 floret in the fertile spicula, has yet no very striking general similarity with 

 Phalaris, and still less with Alopecurus and Phleum, or these with Holcus and 

 Anthoxanthum. Knappia, with its flowei-s on a one-sided rachis, may possibly 

 be more nearly allied to the Chloridece, where it is placed by Reichenbach : 

 yet on the whole I am disposed to keep it in the neighbourhood of Agrostis. 

 Among the Panicece, Milium effusum seems oddly introduced between the two 

 closely allied genera Paspalum and Panicum. To make out its claim to a 

 place in the Panicece, we must suppose that of the two very similar outer 

 glumes, which are usually considered as forming the calyx, one only deserves 

 that name, while the other is to be taken as an abortive floret. These suppo- 

 sitions (unsupported by any peculiarities in the construction) may affbrd 

 grounds for ingenious speculations, but they can hardly be made use of as 

 parts of a generic character ; or, to use the words of De Candolle, "such an 

 hypothesis may be convenient if considered as an image or a metaphor, but 

 can hardly be allowed as an expression of reality." 



Kunth has not only scattered into three genera the species of the Linnean 

 genus Milium, but he has placed these in three different families. Milium 

 effusum, retaining the ancient name, is, as we have just seen, put among the 

 Panicece; M. ccerulescens, M. paradoxum, &c. form the genus Piptatherum, 

 which is one of the Stipacece ; and M. lendigerum, under the name of Gastri- 

 dium, is found among the Agrostidece. The Arundinacece consist entirely of 

 genera formed out of the Linnean Arundo. The Chloridece are, perhaps, not 

 very closely allied, at least there seems little afiinity between Cynodon and Spar- 

 tina except in the inflorescence. Koeleria among the Festucacece trenches very 



