[Vor. 4 
62 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
only by the entirely different sepals, but by the straight yel- 
low anthers, the very much shorter stigmas, and slightly in 
the shape of the leaves. 
The variety stenosepalum is nearly related to Т. ovatum, 
and all the specimens cited from Californian localities have 
hitherto been included under the latter species. It is impos- 
sible, however, to include under one name forms which differ 
so widely, especially in their sepal characters. Т. ovatum was 
originally described from Washington, and extends south- 
wards into northern California in Humboldt and Mendocino 
Counties. Specimens belonging to it also occur apparently 
in Santa Cruz County. It differs from the variety steno- 
sepalum chiefly in that the petals turn pink in drying and the 
sepals are broader. The two forms overlap in Washington 
State, but the variety extends further east and south. In 
certain intermediate areas there appear to be transition 
forms as regards width of sepals, but specimens of the 
variety from Montana are entirely distinct from specimens 
of the species proper from Washington. However, certain 
specimens having sepals of the species do not turn pink in 
drying, while the petals of typical forms of the variety do 
occasionally turn pink in drying. Hence it seems necessary 
to regard the variety stenosepalum as a transitional variety. 
Apparently continuous intermediate series occur between 
all three forms, T. ovatum, the variety stenosepalum, and Т. 
venosum, in intermediate geographic areas. This appears to 
be a case of continuous geographic variation, yet in their 
typical form they are so different that all three forms require 
separate recognition. The sepal differences are the most 
conspicuous, the sepals varying from 2 cm. wide with 3 prom- 
inent nerves in 7’. venosum, to 3 mm. wide without visible 
nerves in var. stenosepalum. 
Specimens examined: 
Montana: Helena, 1891, Alderson (E. Starz, Herb. Whelp- 
ley), two specimens (Mo. Bot. Gard. Herb.), TYPE. 
Idaho: Paradise Hills, Latab Co., April 18, 1900, Le Roy 
Abrams 548 (Univ. Cal. Herb., 13751); Lake Waha, Nez 
