1917] Blake,— Varieties of Chimaphila umbellata 239 
true value and the relationship of the plants concerned are consider- 
ably obscured by a treatment which ranks all of these as species. 
Thus C. domingensis, whose presence so far from the normal range of 
the genus may be compared with that of the remarkable Crossbill ! 
recently discovered in the mountains of the same island, is sharply 
separated from all the other plants of this group by its ovate glabrous 
filaments, its perfectly glabrous peduncles and pedicels, very small 
and bluntly few-toothed leaves, and finely erose but scarcely glandu- 
lar-ciliolate sepals. On the other hand, the plants called by Ryd- 
berg C. umbellata, C. occidentalis, C. corymbosa, C. mexicana, and C. 
acuta agree in the possession of obovate ciliolate filaments, densely 
glandular-granular peduncles and pedicels, larger more or less sharply 
toothed leaves, and ciliolate sepals; while the differential characters 
brought forward for their specific separation are confined to differ- 
ences in size, in the prominence of the venation, the shape of the 
sepals, the direction of the pedicels, and the rotundity of the stem, 
characters which are not only rather obscure but at best are merely 
comparative, and are shown by the material examined to be by no 
means absolutely constant. Thus the venation in the leaves of 
western specimens of C. umbellata is sometimes although rarely nearly 
or quite as prominent as in eastern plants, while the shape of the stem, 
in herbarium specimens at least, is not to be depended upon to dis- 
tinguish specimens from the two areas; and the character of the 
pedicels, whether ascending or spreading, is a feature not without 
variation in both forms. Both the eastern and western forms of the 
United States not infrequently attain the dimensions assigned to 
the Mexican form. The fruits of the Mexican specimens examined 
measure 7.5-8.5 mm. in diameter, none of them being “nearly 1 em.” 
thick, while in some of the western examples (C. occidentalis) capsules 
7.5 mm. in diameter are found. In seven sheets of the southwestern 
form (C. acuta), including the type, not more than half have the ovate 
acute sepals on which the species was based, although they do show 
diagnostic and constant characters in the shape and toothing of their 
leaves. In fact, the variation in sepal-form in the seven sheets from 
this region (Arizona and New Mexico) is greater than that shown by 
all the other specimens of C. umbellata (sensu lato) which I have 
examined from Eurasia, North America, and Mexico. 
1 Loxia megaplaga Riley, Smiths. Misc. Coll. Ixvi. no. 1. 15 (1916). 
