1917] 
GATES—THE GENUS TRILLIUM 67 
bus divergentibus apicibus recurvatibus ovario flavo ex- 
cedentibus. 
Stem stout, 5-10 mm. in diameter, 2-3.5 dm. high, purplish, 
sheathed at base for a distance of 6 ст.; leaves rhomboid- 
ovate, 5-7-nerved, 6-11 em. long, 5-8 em. wide, acute, short- 
acuminate; peduncle 3 em. long, erect, purplish, 2 mm. thick; 
sepals large, and with 3-5 prominent veins, oblong-lanceolate, 
broad-pointed, 3.5-5.8 em. in length, 14-20 mm. in width; 
petals white, ovate-oblong, obtuse-pointed, with crisped mar- 
gins, 3.5-5.5 em. long and 1.4-1.5 em. wide; anthers 8-15 mm. 
long, bright pink, curved outwards at the summits, slightly 
surpassing the stigmas, filaments about 5 mm. long, dilated 
at base; stigmas slender, 10 mm. in length, somewhat diver- 
gent, recurved at the tip; ovary yellow, about 10 mm. long. 
This species is nearest T. Scouleri, of which I have not seen 
specimens. In Rydberg's description of that species the 
sepals are not mentioned, but the large conspicuously veined 
sepals of Т. venosum could scarcely have been overlooked had 
they been present on Rydberg’s species. The present species 
is intermediate between T. grandiflorum and T. ovatum in 
size and shape of petals and length of anthers. In specimens 
of T. grandiflorum from the more western part of its range, 
e.g., Milwaukee, Wis., the sepals are 5-nerved but they are 
much narrower and the veins are less prominent than in 7’. 
venosum. 
The main distinctions of T. venosum from T. Scouleri are 
in the broad sepals with their prominent veins, the pink color 
of the anthers, and the 5 rather prominent veins of the leaves. 
The petals appear to resemble closely those of T. grandiflorum 
in several features. 
Specimens examined: 
Dry Buck, Boise Co., Idaho, 10 May, 1911, J. Francis Mac- 
bride 847 (Mo. Bot. Gard. Herb. and Univ. Cal. Herb., 
163236), түре. I reproduce here the cotype specimen because 
it is larger than the type specimen and shows the characters 
better. 
The following specimens come nearest to Т. venosum but 
differ in certain features: 
