PAPERS ON BOTANY 



113 



very bairv buds. The jack oak has buds more nearly like 

 those of the eastern scarlet oak though smaller, — distinctly 

 smaller and usually blunter than those of the black oak 

 and, like those of Q. coccinea, different from those of the 

 red and pin oaks in being more or less silky pubescent. 

 This is a character that varies somewhat in the scarlet 

 oak. In Q. ellipsoidaUs there is still greater variability, 

 for some trees have nearly glabrous buds, and others dis- 

 tinctly canescent buds. One of the earliest students of 

 bud characters in this country, Dr. Brendel of Peoria, for 

 whom what we now know as Qiiercus velutina represented 

 the scarlet oak, records! that after coming to believe that 

 he had found a dependable character for this in its large 

 pubescent angular buds his faith in this mark was shaken 

 by finding that the cocci nea of northern Illinois has round 

 and smaller buds more like those of the red oak, — this of 

 course referring to the clUpsoidaJis aggregate of forms, 

 shortly afterward differentiated though not separated 

 from coccinea by Vasey. 



Though the extremes under which the acorns of Qucrcus 

 ellipsoidaUs occur pass into one another so that the recog- 

 nition of forms based on them is scarcely more than a con- 

 venient way of ensuring their reference to this alliance, 

 the fruit of a given tree is fairly uniform : and in this 

 respect the trees will probably be found to breed true. 

 Whether this is equally likely for the different foliage 

 forms seems questionable : but this has never been tested, 

 so far as I know, for either this species or the still more 

 variable black oak. As yet, I have been unable to correlate 

 the bark, bud, foliage, and fruit dift'erences that have 

 been observed, so that for the present it seems possible to 

 differentiate the forms only on the following characters : — 

 Leaves broadly elliptic, regularly pinnatifid. 



Cup more or less turbinate, not dilated much beyond the 

 diameter of the acorn. 



Acorn elongated, about in the ratio of 2 :3. 



Scales of cup not incurved, Q. ellipsoidaUs Hill. 

 Scales incurved about the acorn, f. incurva Trel, 

 Acorn broadly ovoid, about in the ration 



of 3:4. f. intermedia Vasey. 



Acorn subglobose. f. depressa Vasey. 



JAmer. NaturaUst 4 :24S. 1870, 



