238 Rhodora [NOVEMBER 
into at least four geographically isolated varieties. One of the 
differences between the American and European forms had been noted 
by J. E. Smith as long ago as 1814 (“1819”), in his revision of the 
genus for Rees’s Encyclopaedia (xxix. no. 11), where he remarks, 
after describing Pyrola umbellata: “The American specimens are 
usually less umbellate, and more racemose, than the European.” 
In his recent revision of Chimaphila in the North American Flora,! 
Dr. Rydberg has restricted C. umbellata to Europe and divided the 
North American material hitherto referred to that species into four. 
One of these, C. mexicana, is the Mexican plant distinguished as a 
variety by DeCandolle in 1839. The eastern plant is called C. 
corymbosa, a name proposed by Pursh in 1814 as a new name for the 
transferred Pyrola umbellata of Linnaeus. A western plant, C. occi- 
dentalis, ranging from British Columbia to California, is described, 
and a southwestern one, C. acuta, from Arizona and New Mexico. 
Of the true Chimaphila umbellata Dr. Rydberg says:? “This is a 
European species with which our American species has been confused, 
differing from C. corymbosa in the smaller subovoid capsule, which is 
thicker below the middle, ovate sepals, longer than broad, shorter 
stamens, and obtusish leaf-blades. Alefeld, who distinguished the 
two, admitted C. wmbellata to the west coast, but his specimens were 
evidently depauperate northern ones of C. occidentalis.” The diag- 
nostic characters of the American representatives of C. umbellata are 
thus indicated in Dr. Rydberg’s key. 
Dilated portion of the filaments glabrous or merely ciliolate on the margin; 
leaves oblanceolate or spatulate, not mottled. 
Sepals fully as broad as long, mostly obtuse. 
Leaf-blades with rather indistinct lateral veins; pedicels ascending, 
not recurved; stem terete.............. 1. C. occidentalis. 
Leaf-blades with more prominent lateral veins; pedicels in anthesis 
spreading, recurved; stem more or less round-angled. 
Plant 1-2 dm. high; capsule 5-6 mm. in diameter. 
Dilated portion of the filaments obovate, ciliolate; pedicels 
glandular-granuliferous............... 2. C. corymbosa. 
Dilated portion of the filaments ovate, not ciliolate; pedi- 
cels MADIOUS. .. 6255 4555.nss Bs 3. C. domingensis. 
¿ Plant 2-3 dm. high; capsule nearly 1 cm. in diameter. 
C. mexicana. 
Sepals longer than broad, acute................ceece0e: 5. C. acuta. 
While the differential characters brought out in this key are con- 
firmed for the most part by the abundant material examined, their 
1 Rydb. in Britton, N. Am. FI, xxix. 30-32 (1914). 
2 Rydb. 1l. c. 32. 
