l/'aria/ioiis and lutcrviediale Forms of Certain Asters. 55 



VARIATIONvS AND INTERMEDIATE FORMS OF 

 CERTAIN ASTERS. 



By W. C. Wkrnkk. 



Assistant in Botany, Ohio State University. 



Read at the ineetin.1^ for the formation of the Ohio Academy of 

 Science, December 30, 1891. 



Of otir native (lowering plant.s the asters are among the 

 mo.st difficult for the sy.steniati.st to dispose of. This is quite 

 discouraging to the amatetir botanist who wishes to study the 

 genus. Color can not be depended on ; every character laid 

 down in the books is more or less inconstant. This is 

 especially noticeable in the section Hctcrop/iy/li, the subject 

 of this paper. 



In Gray's Manual, in the description of y^,s7<?/- Shortii, Hook., 

 the words " naked petioles" are emphasized by italics, yet I 

 find undoubted forms of this species with winged petioles. 



Again I find Aster undiilalus, L., meeting A. Shortii half 

 way. 



I can not draw a distinctive line between the outlying forms 

 of the two species, which approach and apparently meet. 



I find the same state of afi"airs existing between Aster 

 undulatus and Aster cordifolius. When I came to Columl)Us, 

 a year ago, the common blue aster in the immediate vicinity 

 of the city was of considerable interest to me, for two reasons, 

 viz : because of its polymorphic habit, and its persistence in 

 evading every description of the books. Coming nearest to 

 Aster sagittifolius, Willd., some of the extremely large-leaved 

 and larger flowered forms I thought might be A. Lindleyanus. 



The latter, however, is a strictly northern species ; Labrador 

 to Lake Superior, Saskatchewan, borders of British Colum- 

 bia and New Hampshire is the range given in Gray's Manual 

 and the Synoptical F'lora. During October I looked for varia- 

 tions that might connect the ordinary form of A. sagittifolius 

 with that answering to the description of A. Undleyanus. 



