1913] Brainerd,— Viola arenaria 107 
the two hemispheres are of the same species. Through the kindness 
of Dr. Millspaugh, of the Field Museum, Chicago, I have had the loan 
for several months of 45 excellent specimens of the European V. aren- 
aria, and of 577 additional specimens of allied European species of 
the canina group. The opportunity thus afforded for a careful 
comparison has convinced me beyond a doubt that our so-called V. 
arenaria is specifically different from the Old World V. arenaria DC. 
Without going into a detailed discussion of the points of difference, 
I would present them concisely in the following table: — (See plate 
104.) 
V. RUPESTRIS Var. ARENARIA (DC.) Beck. AMERICAN ALLY 
Leaves: roundish, not much longer than broadly ovate, bluntly 
wide, rarely over 2 cm. long; pointed, usually 2-5 em. long. 
STIPULES: ovate to oblong, with acute linear to lanceolate, with scat- 
close-set deltoid teeth; tered setulose teeth mostly 
near the base. 
FLOwERs: much overtopping the leaves; slightly overtopping the 
leaves. 
Bracts of peduncles usually on a level usually much below the 
with the flower; flowers. 
PETALs: broadly obovate, 4-6 mm. wide; narrowly obovate, commonly 
3-4 mm. wide. 
SPUR: 3-4 mm. long, straight, blunt; 5-7 mm. long, often curved 
upward or hooked. 
CAPSULE: pubescent; glabrous. 
It should be noted that occasional specimens from the Old World 
labeled * V. arenaria" are not typical, but rather hybrids of this with 
allied species of the same group. Six such hybrids are listed in W. 
Becker's VroLAE EUROPAEAE; some of them closely simulate the 
American plant. 
The task, then, is before us to determine what name, if not V. 
arenaria nor V. rupestris, rightfully belongs to our native species. We 
note, first, that though the plant is not infrequent along the whole 
northern border of the eastern United States and adjacent Canada, 
its occurrence in this tract was not recognized until within the last 
twenty-five years. Dr. Gray, indeed, had once before him a specimen 
collected by Dr. Engelmann in loose sands on the shore of Lake 
Superior; but he considered it “a summer form" of V. canina var. 
