50 Rhodora [Marcu 
to have somewhat wedge-shaped small blades (0.7-2.5 cm. long 
and broad), and the petals of this mountain plant are only 4-6 mm. 
long and 2.5-4 mm. broad. These are the superficial differences 
between the two plants, but close study reveals others. The large- 
leaved, large-flowered, more southern plant has a broader calyx, 
4.8-6 mm. broad with lobes 1.2-2 mm. long, the plant of northern 
New England having a calyx 3-4 mm. broad, with lobes 0.5-1 mm. 
long. The anthers of the more southern plant are 3-4, of the more 
northern 1.6-2.6 mm. long, and the mature style (in fruiting speci- 
mens) of the southern is 8-10, of the northern 5-7 mm. long. 
If these two were the only representatives we had of Pyrola 
chlorantha, they would seem abundantly distinct. But north of the 
range of either, though slightly overlapping into the range of each, 
there is a third trend which combines their characteristics. "This 
plant with numerous rounded leaves forming a conspicuous rosette 
superficially resembles Barton's P. convoluta, but the leaf-blades are 
commonly smaller, while the calyx, petals, anthers and style more 
nearly approach in their measurements the few-leaved plant with 
usually cuneate small blades. This more northern intermediate 
plant, ranging from Newfoundland and “Labrador” to Mackenzie 
and south very locally to New England, the Great Lake Region, 
the Black Hills, Arizona and Oregon, is typical P. chlorantha, in- 
separable apparently from the plant of northern Eurasia. 
In the Rocky Mountain region occurs a somewhat characteristic 
extreme with elliptic or oblong-ovate leaf-blades but seeming to 
differ in no other character from typical P. chlorantha. "This plant 
was considered by Dr. Gray identical with P. occidentalis R. Br. 
from the Behring Sea region and treated as P. chlorantha, var. occi- 
dentalis (R. Br.) Gray.! It is highly improbable, however, that the 
two are identical, Andres, who has devoted years to a study of Pyrola, 
stating? that the sepals of P. occidentalis are larger than in P. chlor- 
antha and publishing a silhouette of an Alaskan specimen which 
shows a rounder blade than in the elliptic-leaved Rocky Mountain 
plant. 
In the West, too, certain plants commonly referred to P. chlorantha 
are equally close to P. picta Sm. These perplexing plants are all 
from the area in which the latter species occurs and may represent 
! Gray, Syn. Fl. N. A. ii. pt. 1, 47 (1878). 
2 Andres, Allgem. Bot. Zeitschr. xix. 82 (1914). 
