53 



t 



OBSERVATIONS ON THE COMPOSITiE.— IV. 



By Edwakd L. Gkeene. 



Trihe III: Astere^. 



Between tliis extensive series of genera and tlie Eupa- 

 toriaceae the passage is somewhat abrupt, whether w^e look to 

 the natural qualities or the botanical characters of the two 

 tribes or suborders. Many, or perhaps even most Eupatori- 

 aceous plants are aromatic, bitter, and possessed of recognized 

 tonic and other medicinal qualities. The Aster ese have a 

 bland watery juice, a scentless herbage, and no active 

 properties of any kind, save that in some there is a gummy — 

 or rather balsamic or resinous — exudation on the foliage and 

 inflorescence; but this, if not inactive, is almost odorless. 



In botanical characters there seem to be no transitions 

 between the two groups. There are no elongated-clavell- 

 iform style-branches in the Asterese, nor any short and blunt 

 ones inthe Eupatoriacese; and it is highly probable that to 

 designate the two groups as mere tribes of one natural order 

 is a too feeble statement, based on a superficiality of view.^ 



In North America the Asterese are excessively numerous, 

 and no natural assemblage of plants has seemed to present 

 such difficulties to the systematist; and the widest conceiv- 

 able diversities of opinion as to the limits of genera have 

 found expression among botanists when undertaking to 

 classify them. Groups of species which one author will 

 combine as of one genus, another will distribute through a 

 dozen genera, if not a score. And characters — such as that 

 oE color of flowers — which are of no more than specific value 

 in other orders, and often of less, are here received in some 

 instances as of generic and even subtribal importance; and 

 this not by the hasty and superficial, but by the more careful 

 and cautious of botanists. And many of the most erudite and 

 experienced are observed to advocate views diametrically 

 opposite in respect to the limits of groups, one party main- 



lln the Manual of Bay-Kegion Botany I have called them Suborders. 

 Ebythea. Vol. II., No. i. [1 April, 1894]. 



