1903.] NATURAL SCIENCES OF PHILADELPHIA. 669 



Fruitino- scapes 140 mm. long. Leaves 50 x 70, glabrous; petioles 150 

 mm. long, glabrous or with a few scattered hairs. Stolons just sprout- 

 ing, 50 to 60 mm. long. In July and August specimens the stolons 

 bear leaves 20 x 25 mm. on petioles 50 mm. in length, as well as small 

 cleistogenes. In specimens from Willow Grove, jMontgomery county, 

 Pennsylvania, the main leaves reach the dimensions of 60 x 100 mm. 

 on petioles 160 mm. in length, while the erect cleistogenes are on 

 pubescent scapes 80 mm. long. 



This species and the next are open-bog or wet-meadow violets, 

 forming a very distinct group from the woodland, rocky-bank species 

 which precede; and seem to be the southern representatives of the 

 blanda group. We have thus tw^o austral species and three boreal 

 ones, the members of each group more closely related inter se than 

 they are to any species of the other group. Among vertebrates in a 

 similarly distributed lot of forms we should expect to find boreal and 

 austral derivatives of the several types, but as before stated, in plants 

 we seem to find that the most recent differentiations have taken place 

 within the same life-zone, and that they are not zonal in their origin or 

 distribution. 



5. Viola lanceolata Linn. 



Viola lanceolata Linn., 1753, Sp. Plant., pi. 953. 



Viola attenuata "Sweet" Don, 1831, Gen. Syst., I, p. 322. 



Range.— The southeastern counties of Pennsylvania, mainly along 

 the Delaware and Susquehanna (also ]\Ionroe county— Porter), and 

 abundant throughout southern New Jersey, where it is the most char- 

 acteristic species of the pine-barren bogs, also up the Delaware to 

 Warren county (Britton). About Philadelphia it is found only in the 

 low grounds along the Delaware. 



Habitat.— Wet open bogs or meadows, often growing with V. pri- 

 mulcefolia, and sometimes approaching it in early leaf-forms, but the 

 flowers are always larger, and the later leaves abundantly distinct. 



Descriptio7i. — Early flowering plant. Tinicum, Delaware county, 

 Pennsylvania, May 9, 1903. No. 5,156, Herb. W. S. Flowers 15 mm. 

 wide, white, the lower petal strongly purple-veined, the laterals with 

 one or two streaks; glabrous; sepals narrowly linear, acute, scapes 

 glabrous, 100 mm. long. Leaves ovate-lanceolate, decurrent at base, 

 35 X 12 mm., obscurely crcnulate glabrous, petioles glabrous, 30-40 

 mm. Cleistogenes on scapes 30 mm. long. 



Later plants have leaves lanceolate, gradually decurrent, length 

 including petiole 175 mm., width 15 mm. Flower scapes 170 mm. 



Fruiting plant. Tinicum, June 28, 1903. No. 5,157, Herb. W. S. 



