682 Violaceae Viola 



to separate are our numbers 2 and 4, 8 and 10, 16 and 17a, and 18 and 19. 

 Dr. E. L. Greene was also a profound student of violets and named some 

 of my specimens. Since I have followed Brainerd's treatment of the genus, 

 I have made Greene's determinations conform with it. 



KEY TO SPECIES BASED ON PETALIFEROUS FLOWERS 



Plants stemless; leaves and scapes all from rootstocks or runners. 



All petals beardless; cleistogamous flowers wanting 1. V. pedata. 



All petals usually not beardless ; cleistogamous flowers present. 



Rootstocks stout, (2.5) 3-10 mm in diameter, short, without stolons; flowers blue 



or violet, sometimes nearly white, rarely white and blotched with blue or 



purple, or in one species a part of the flower white and the rest blue. 



Leaves truncate or cuneate at the base, all or all except the earliest, 5-11 (-15)- 



lobed or -parted, all of the segments usually narrow; plants more or less 



pubescent. 



Spurred petal glabrous; leaves 5-11-lobed or -parted; flowers on peduncles 



shorter than the leaves. (See excluded species no. 456, p. 1075.) 



.V. palmata. 



Spurred petal bearded; leaves 3-parted or -divided, each segment again 

 usually 3-cleft or -parted and these generally further divided into 2-4 

 linear segments; flowers on peduncles generally longer than the leaves. 



2. V. pedatifida. 



Leaves cordate at the base. 



Blades or at least some of them, lobed or parted. 



Leaves or some of them, 3-lobed or -parted, the segments large and usually 

 more or less lobed or deeply toothed or the middle one entire; plants 



pubescent; spurred petal glabrous or bearded 3. V. triloba. 



Leaves 3-7-lobed or -parted, middle segment broad, acute, serrate, the basal 

 ones sinuately serrate; plants glabrous; spurred petal glabrous. (See 



excluded species no. 460, p. 1075.) V. viarum. 



Blades not lobed or cut, most of the vernal ones more than 2.5 cm wide. 



Beard of lateral petals generally of strongly clavate hairs; spurred petal 



glabrous, shorter than the lateral petals; flowers on peduncles much 



exceeding the leaves, with a dark eye; cleistogamous flowers on long 



slender, erect peduncles; plants glabrous, of cold springy places and 



bogs 4. V. cucullata. 



Beard of lateral petals of cylindrical or only slightly clavate hairs; spurred 

 petal glabrous or bearded, equaling or longer than the lateral petals ; 

 flowers on peduncles shorter than or only slightly exceeding the leaves, 

 with a white or yellow eye; cleistogamous flowers on prostrate, spread- 

 ing peduncles; plants of wet or moist places. 

 Plants essentially glabrous, sometimes some of the petioles and some of 

 the leaves more or less pubescent (the pubescence a sign of hybrid- 

 ization). 

 Spurred petal glabrous or nearly so. 



Vernal leaves ovate-deltoid; flowers on peduncles generally as long 

 as or longer than the leaves, pale violet to nearly white, with a 

 darker band above the pale eye; sepals with a white margin; 

 cleistogamous flowers on short, prostrate peduncles, their cap- 

 sules dotted with brown; plants of wet places 



5. V. missouriensis. 



Vernal leaves reniform to ovate; flowers on peduncles usually shorter 

 than or as long as the leaves and in some early specimens 

 slightly longer, deep purple, with a white or yellow eye; margins 



