questionable, are noticed as such in their proper places. I have rejected many synonyms of the old authors, from motives of caution: but I am inclined to believe that every species enumerated by them refers to some one or other of the plants here recorded.
It was deemed necessary to be more particular in describing the varieties than is customary in a scientific paper; not only because some of these may hereafter turn out to be distinct species, but also with a view to render the tract useful to cultivators as well as to botanists; and by referring each plant at present known to the old authors, in all cases in which they can be followed, to guard in future, as much as possible, against the confusion which their inaccuracies have produced.
I have rejected the folium ternatum in the specific characters, as being common to the whole: and for the same reason I have avoided in the descriptions the repetitions of such terms as caulis uniflorus, caulis angulatus, petioli supra canaliculati. The number of stamina is also omitted, as being very indefinite.
There are two parts, however, in the organization of the Pæonies, which appear to me to deserve more attention than has been paid to them; but they attracted my notice when it was too late for me to avail myself of them: viz. the shape and number of the stipulæ attached to the caudex, and the form and structure of the perigynous substance which belongs to all the species. These may perhaps hereafter form important objects for specific distinction.
All the species hitherto known are confined to the northern hemisphere, and no one has yet been found in any part of America. They belong to cold climates. Some species indeed are indigenous in the south of Europe; but they grow upon elevated situations. They are, as far as has yet been tried, sufficiently hardy to stand our winter unprotected.
