1898 ] EASTERN ACAULESCENT VIOLETS 327 
grading characters.’’ Indeed in a recent important volume 
dealing with systematic botany in this country the statement is 
made in a footnote that ‘‘the contour of the leaf, varying upon 
the same individual from reniform to ovate and acute, affords no 
satisfactory distinction.’”’ Such a remarkable variation can 
scarcely be manifest to the ordinary observer unless the charac- 
terless primitive foliage is taken into consideration. With equal 
consistency and discrimination we might attempt to compare the 
various species of Ipomoea upon the basis of their remarkably 
uniform bilobed cotyledons. In two or three of our eastern 
violets leaf-contour, with respect to the mature foliage, plays an 
important part in differentiating the species. If it were not for 
the trigonous outline of the leaf of V. emarginata, for example, 
that species might by those unfamiliar with the habits of violets 
be confused with V. sagittata; but the elongated lanceolate blade 
of the latter cannot fail to render it distinct to any observer. 
In the subjoined key I have followed the primary division of 
Dr. Gray and other authorities, separating V. pedata as a distinct 
class on account of the characters found in the rootstock and 
stigma. The remaining divisions are somewhat arbitrary, as I 
fully realize the futility of constructing any key inthe hope that it 
will afford conclusive determinations of every unusual form. To 
the larger divisions have been given group names, partly for the 
sake of convenience, and partly in order to make clear the 
affinities of each species. A knowledge of these primary groups 
is often indispensable in determining a violet of doubtful rela- 
tionship. The key includes all the acaulescent species east of 
the Mississippi now known to me, with the exception of the 
Canadian forms recently described by Professor Greene? In 
the notes following the key are mentioned only those 7 aaa 
deserving special comment. 
SECTION I. 
Leaves and flowering scapes directly from a short, erect caudex ; plants 
not stoloniferous ; cleistogamous apetalous newer apparently wanting ; 
_ Petals beardless, blue; stigma large, not rostrate. 
CLASS 1, Pedate. ‘ 1. V. pedata 
$ Pitt. 3 : 333 ef seg. 
