The American Violet Society
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Simplified Dichotomous Key To
The Viola of Pennsylvania
By Gary W. Sherwin
Compiled From A Key By Harvey Ballard
Originally Published In Plants of Pennsylvania

© 2001 The American Violet Society All Rights Reserved
Photos by Gary W. Sherwin & Darryl Goodman

CLICK ON SPECIES IMAGE FOR ADDITIONAL INFORMATION AND PHOTOS OF EACH SPECIES

START
HERE
  Comparison 
1		   Comparison  
2		   Comparison
3		   Comparison 
4		   Comparison 
5		   Comparison 
6		   Comparison 
7		   Comparison 
8		   Comparison 
9		   Comparison 
10		   Comparison 
11		   Final
Answer
A1   Stemmed
B1  
  Without yellow center
C1      
  Corolla creamy-white
         
  V. striata
              Click Here For A Description And Pictures Of Viola Striata
C2         Corolla blue or pale purple
D1      
  Laterals bearded
       
  V. labradorica
            Click Here For A Description And Pictures Of Viola labradorica
D2           Laterals not bearded
       
  V. rostrata
            Click Here For A Description And Pictures Of Viola rostrata
       
     
B2     With yellow center
E1    
  Slender Taproots
F1      
  Leaf blade 0 to 2 crenations
       
  V. bicolor
            Click Here For A Description And Pictures Of Viola bicolor
F2           Leaf blade 3+ crenations
G1          
  Corolla cream-white
         
  V. arvensis
              Click Here For A Description And Pictures Of Viola arvensis
G2           Corolla yellow-orange to purple
         
  V. tricolor
              Click Here For A Description And Pictures Of Viola tricolor
         
       
E2       Rhizome > 3 mm thick
H1      
  Corolla white
       
  V. canadensis
            Click Here For A Description And Pictures Of Viola canadensis
H2         Corolla yellow
I1        
  Leaves broad as long or wider
         
  V. pubescens
              Click Here For A Description And Pictures Of Viola pubescens
I2           Leaves much longer than wide
J1          
  Leaves arrow shaped
           
  V.hastata
               
J2             Leaves lance-ovate
           
  V.tripartita
                Click Here For A Description And Pictures Of Viola triparita
           
         
       
     
                       
A2   Stemless
K1  
  Corolla yellow
   
  V. rotundifolia
       
K2     Corolla white to blue
L1    
  Leaves densely pubescent
     
  V. odorata
          Click Here For A Description And Pictures Of Viola odorata
L2       Leaves sparsely hairy upper otherwise glabrous
M1      
  Spur longer than thick
N1        
  Lateral petals bearded
         
  V. appalachiensis
              Click Here For A Description And Pictures Of Viola appalachiensis
N2           Lateral petals not bearded
         
  V. selkirkii
              Click Here For A Description And Pictures Of Viola selkirikii
         
M2         Spur shorter than thick 2 mm or less long
O1        
  Corolla entirely white often with brown to purple lines
P1          
  Leaves > 1.5 times long as broad
Q1            
  Black gland on each leaf tooth, Tapered leaf base
             
  V. lanceolata
                  Click Here For A Description And Pictures Of Viola lanceolata
Q2               No black gland on each leaf tooth, Square leaf base
             
  V. primulifolia
                  Click Here For A Description And Pictures Of Viola primulifolia
               
P2             Leaves < 1.5 times long as broad often broader than long
R1            
  Leaf underside not paler than upper, BLADES absolutely hairless
             
  V. macloskeyi
                  Click Here For A Description And Pictures Of Viola macloskeyi
R2               Leaf underside paler than upper BLADES some hairs
S1              
  Rhizome horizontal, Stolons on mature plants
               
  V. blanda
                    Click Here For A Description And Pictures Of Viola blanda
S2                 Rhizome vertical, Never produces stolons
               
  V. renifolia
                    Click Here For A Description And Pictures Of Viola renifolia
               
             
           
O2             Corolla blue to violet rarely white with a purple center
T1          
  Leaves lobed or dissected
U1            
  Lobes dissected nearly to base
V1              
  Lateral petals glabrous
               
  V. pedata
                    Click Here For A Description And Pictures Of Viola pedata
V2                 Lateral petals bearded
               
  V. brittoniana
                    Click Here For A Description And Pictures Of Viola brittoniana
               
U2               Lobes cut about halfway to base
W1              
  Leaves much longer than broad, teeth or lobes < 1/3 base of blade
               
  V. sagittata    
WA1                   Leaves Deeply Lobed Base
                 
  V. sagittata -f- sagittata
                      Click Here For A Description And Pictures Of Viola sagittata f sagittata
WA2                   Leaves Serrated Base
                 
  V. sagittata -f- ovata
                      Click Here For A Description And Pictures Of Viola sagittata f ovata
                 
W2                 Leaves not longer than broad, reaching to or beyond margin
X1                
  Some leaves lobed, others not
                 
  V. palmata
                      Click Here For A Description And Pictures Of Viola palmata
X2                   All leaves lobed
                 
  V. subsinuata
                      Click Here For A Description And Pictures Of Viola subsinuata
                 
               
             
T2             Leaves merely serrate along margins
Y1            
  Leaves longer than broad
Z1              
  Foliage pubescent
               
  V. sagittata    
ZA1                     Leaves Deeply Lobed Base
                 
  V. sagittata -f- sagittata
                      Click Here For A Description And Pictures Of Viola sagittata f sagittata
ZA2                   Leaves Serrated Base
                 
  V. sagittata -f- ovata
                      Click Here For A Description And Pictures Of Viola sagittata f ovata
                 
Z2                 Foliage not pubescent
AA1                
  Spurred petal bearded, Lateral petal hairs linear
                 
  V. affinis
                      Click Here For A Description And Pictures Of Viola affinis
AA2                   Spurred petal not bearded Lateral petal hairs knob ended
                 
  V. cucullata
                      Click Here For A Description And Pictures Of Viola cuculatta
                 
               
Y2                
BB1              
  Sepals sharply acute at the tip
               
  V. cucullata
                    Click Here For A Description And Pictures Of Viola cuculatta
BB2                 Sepals obtuse to rounded tip
CC1                
  Spurred petal bearded
                 
  V. hirsutula
                      Click Here For A Description And Pictures Of Viola hirsutula
CC2                   Spurred petal not bearded
                 
  V. sororia  
DD1                     Petals Predominantly Blue To Violet 
                   
  V. sororia
                        Click Here For A Description And Pictures Of Viola sororia
DD2                     Petals Predominantly White to Gray
EE1                    
  Petals white to gray with blue blush center
                     
  V. sororia-f-priceana
                        Click Here For A Description And Pictures Of Viola sororia f priceana
EE2                       Petals pure white except for striation
                     
  V. sororia-f-albiflora
                        Click Here For A Description And Pictures Of Viola sororia f incognita
                     
                   
                 
               
             
           
             
         
     
 
  Comparison 
1		   Comparison 
2		   Comparison 
3		   Comparison 
4		   Comparison 
5		   Comparison 
6		   Comparison 
7		   Comparison 
8		   Comparison 
9		   Comparison 
10		   Comparison 
11		   Final
Answer
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