662 PROCEEDINGS OF THE ACADEMY OF [Oct., 



the mature leaves are lobed or cut the early leaves are often quite or 

 nearly entire, indicating the probable derivation of lobed-leafed s]X^cies 

 from an entire-leaved ancestor; and the tendency toward lobatior 

 seems to increase in all the later leaves. 



Considering now the racial variations presented by the leaves, we 

 find a tendency in two directions, starting from what I take to be the 

 most primitive type — the cordate leaf of V. 'papilionacea, etc. In one 

 direction we tend toward extreme lobing or leaf division, passing suc- 

 cessively through V. palmata dilatata, V. palmata, V. p. variahilis, 

 V. p. angellcc, V. septcmloha and V. brittoniana, culminating with the 

 aberrant V. pedata, in which the lobation is of a somewhat different 

 type. 



In the other direction, we pass through V. fimhriatida and its forms 

 to the triangular-leaved T'^. emarginata and the narrow sagittate-leaved 

 V. sagittata. This series has a tendency to toothed or notched bases 

 to the leaves, and in very broad-leaved V. emarginata these teeth are 

 exaggerated into lobes and a leaf-form is produced that comes very 

 close to some of the V. palmata group near the other end of the series ! 



Individual variation is best shown in V. p. dilatata and V. p. varia- 

 hilis. In these we are likely to find every variation, from a plain 

 cordate leaf to one with from three to seven lobes, in the same colony 

 of plants, and many of them actually on the same individual plant. 

 Sometimes, too, we find leaves lobed on one side and not on the other. 

 That these all belong to one race is certain, though the unlobed type 

 has often been regarded as distinct under the name of V. sororia. 

 That one style of leaf may prevail in one locality and another some- 

 where else seems quite likely, though all the colonies that I have 

 examined exhibit a great variety of shapes. 



So far as the correlation of the lobed-leaved species with peculiar soil 

 conditions, there seems to be only contrary evidence. The V . palmata 

 group are plants of the upland woods, V. septemloha is a moist-woodland 

 violet and V. brittoniana occurs in open sandy ground, usually in moist 

 spots, while V. pedata is a plant of dry sandy banks. 



There does, however, seem to be a tendency toward narrow leaves 

 in many wet-ground species, as seen in the linear divisions of V. brit- 

 toniana and the lanceolate leaves of V. lanceolata and sagittata. . 



In the pubescence of the leaves we have a pretty good specific char- 

 acter, though it seems to decrease somewhat on very old leaves, while 

 very early leaves of V. p. dilatata are nearly glabrous, though the later 

 ones are strongly pubescent. In V. sagittata some colonies have 

 slightly pubescent leaves, while the typical plants are glabrous. 



