Page:An introduction to physiological and systematical botany (1st edition).djvu/485

From Wikisource
Jump to: navigation, search
This page has been validated.

as his B. cernua; C. coronata is his B. frondosa; and C. leucantha, B. pilosa. Some species of Coreopsis indeed have never been found without rays. Linnæus expresses his difficulties on this subject in Phil. Bot. sect. 209, but seems inclined to unite the two genera. A similar ambiguity occurs between Gorteria and Atractylis, Relhania (of the last Order) and Athanasia, and in some degree between Centaurea, Engl. Bot. t. 278, 1673, t. 56, &c., and Carduus or Serratula; only the scales of the calyx of Centaurea generally keep that genus distinct.

I should be much inclined to abolish this Order. Those of its genera which have rudiments of pistils in their radiant florets, as Rudbeckia and Helianthus, would very commodiously range with their near relations in Polygamia superflua, nor are we sure that such radiant florets are in all circumstances abortive, neither can a student often know whether they are so or not. It does not follow, from what has just been observed, that the presence of radiant florets, whether abortive or not,