8 Mr. Woods on the Genera of European Grasses. 



from a general sense of comparative similarity, no two botanists would per- 

 liaps exactly agree. Thus Arrhenathernm, placed by Linnœus among the 

 Avenœ, and declared by Sir J. E. Smith to be an Arena in habit, is transferred 

 by many botanists to Holcus. De CandoUe, or at least Duby, in a work to 

 which De CandoUe's a])probation is attached, and to which his name is added, 

 solves the difficulty by putting Holcus and Arena into one genus. But ac- 

 cording to Kunth, Holcus does not belong to the Arenacew but to tiie Phala- 

 riderr ; and as tlie barren tlower of Arrhenatheruni is the lowest, this genus 

 would belong technically to tb.e second section of Brown, while both Holcus 

 and Arena belong to tiie first; and Kunth, though he places Holcus with the 

 P/ialurideœ, yet fixes Arr/ienatlieruni, in spite of its outer barren floret, among 

 the Arenacetv. In these indeterminate problems, if I may use the expression, 

 no individual can ])e very confident that he is in the right, but tlie question 

 in each particular case will at last be determined by the adherence of the men 

 of the clearest and most comprehensive views, and who have most carefully 

 studied the subject. At present, in the grouping of Grasses, we seem to stand 

 but on the threshold ; and while one distinguished botanist invites ns in one 

 direction and another in another, the bewildered student is at a loss which to 

 pursue. 



Reichenbach, though he has distributed his Grasses into tribes, has pro- 

 bably given his attention more to the detei-mination of species than to the 

 arrangement of genera. His groups are nearly the same as those of Kunth, 

 and the variations which he has introduced are not for the better. 



I mention Kunth last, as it is his grouping which I propose nearly to ado[)t 

 as to the natural arrangement of the genera ; and I jjegin with this part of the 

 subject, because it is the careful consideration of natural affinities which must 

 guide ns in the choice of the characters on which each genus is to be esta- 

 blished. 



This author, in the work to which I have already referred, divides the 

 Grasses into 13 tribes, which, however, he hardly attempts to characterize. 

 He gives no explanation of the motives which induced him to put plants into 

 the same tribe, or to separate them into different ones ; nor is it easy to ex- 

 tract such motives from the short and loose description which he has prefixed 

 to each tribe, and which, short and imperfect as it is, is generally contradicted 



