The very striking variation in regard to presence or absence of the petiole to the involucral leaves has been previously noted. An inspection of a very large number of specimens collected in the vicinity of Columbus and in Perry and Logan counties, as well as of specimens kindly sent for the purpose by Mr. F. H. Burglehaus, Prof. A. Wetzstein, and Supt. H. N. Mertz, shows that petiolate forms occur exclusively in some localities (Northwestern Ohio); in other places the sessile form only obtains (Eastern Ohio); and yet elsewhere both forms are about equally represented (Central Ohio). We can not regard the petiolate forms as in any real sense a variety (much less a distinct species)—since both sessile and petiolate leaves occur in countless cases on the same plant. But where the petiolate form occurs prevailingly or may be exclusively, it would be advantageous to designate the same; therefore I propose as follows: Syndesmon thalictroides f. PETIOLATA nova forma. Involucral leaves prevailingly or exclusively with petioles 2–10 or even 25 or more millimeters in length; otherwise like the typical species. Toledo (F. H. Burglehaus), St. Marys (A. Wetzstein) and West Mansfield, occasionally at Columbus and Rendville. Comparatively few monstrosities were observed. In one case only did merely one leaf and two flowers occur; often but one flower develops though two leaves occur as usual; in a few cases a single small leaf was seen on a pedicel. A more common teratological variation was the elongation of the axis at the usual point of insertion of the flowers and involucral leaves, often distantly separating the leaves with their axillary flowers; in one case the distance between the points of insertion of the leaves was nearly two inches. The sepals are occasionally excessively numerous. A characteristic very prominent is the similarity of the several stems that come from the same root. If one presents the typical form of flowers and leaves almost without exception, the second (and third when present) do the same; if one varies in any respect rarely does the remainder fail to follow suit. This can be seen in the tabulation where two or more stems are indicated—both or all are given (except in Nos. 29, 30 and 49) as observed, in the successive serial numbers. Another instance of the persistency of an idiosyncracy, as we may call it, was observed in some Syndesmons taken from the woods by a gardener at Springfield, Ohio, over forty years ago. The flowers were bountifully double, and the plants have each year since faithfully presented the same striking peculiarity.