283 Notice of a Flora of North America. 



nists who have had the courage to attempt for themselves the 

 study of this vast and most intricate genus, and its congener Soli- 

 dago. We entirely approve of the reduction of many doubtful 

 species to mere varieties of a recognized type ; and it appears that 

 in many cases the approximation of forms was too close to admit 

 even of this distinction : thus, under A. IcBvis, Linn., we have 

 nine synonyms ! whilst only two marked varieties of the plant 

 occurred to the authors, who say, " The large suite of specimens 

 before us have been named for the most part by several distin- 

 guished botanists, whose determinations so seldom accord, that 

 we feel the greater confidence in our own opinion." * * * 

 Now, we are very far from feeling any surprise that these dis- 

 tinguished botanists should not have understood each other in 

 such cases, as indeed their laborious volumes sufficiently prove, 

 and we should have esteemed it very marvellous had it been 

 otherwise. A variety (perhaps in the first instance accidental) 

 is introduced into some one of the botanical gardens of Europe, 

 where it is carefully propagated by division of the root, and in 

 time distributed generally amongst them. It is not difficult to 

 perceive, that such characters as it originally presented are thus 

 perpetuated throughout the series, and the peculiarity of form 

 becomes known, whilst the slight modification of the original 

 type, from which it was derived, is not susceptible of precise 

 definition in terms. Indeed, it may be said, that the characters 

 relied upon for the discrimination of even acknowledged and 

 understood species, are but modifications, more or less marked, 

 of the same general structure, and hence the many difficulties 

 which have arisen, and the perplexed and entangled synonymy 

 with which we have now to contend. We give our authors all 

 credit for what they have done towards removing these difficul- 

 ties, but we feel convinced that some of the species of Willde- 

 now, Alton, and Linnaeus, will ever remain matter of more or 

 less probable conjecture. The section J.si(er proper is subdivided 

 with great care, and such characters as the several groups afford, 

 have been clearly and well defined. We confess, however, that 

 we do not esteem these as of very great value or importance. 

 Helps to the student they undoubtedly are ; but they pass into 

 each other too imperceptibly to be relied upon as certain distinc- 

 tions, and what we have just observed in respect of the discrim- 

 ination of individual species, is almost equally applicable to the 



