7 
THE VIOLETS OF CALIFORNIA 
At the Society’s meeting' Oct. 6, 1918, Mrs. Dudley 
Baird exhibited a set of colored illustrations of California 
violets done by Schuyler Matthews of New York, from 
fresh material and also sets of herbarium specimens, the 
species of which were determined by Dr. Ezra Brainerd, 
the well-known authority on violets. The eighteen 
species known in California are as follows : Viola 
Langsdorfii, (collected only in California at Fort Bragg) ; 
V. glabella ; V. ocellata ; V. euneata ; V. sarmentosa ; 
V. Macloskeyi; V. venosa; V. purpurea; V. Beckwithii; 
V. Sheltonii; V. praemorsa; V. chrysantha; V. adunca; 
V. lobata; V. Hallii; V. pedunculata; V. occidentals ; 
V. nephrophylla. 
ECOLOGY OF YOSEMITE PARK 
At the meeting on Dec. 14, 1918, Professor H. E. 
McMinn of Mills College lectured on the “Ecological 
Distribution of Plants in Yosemite National Park.” 
The lecturer first described the general topography of 
the region and its relation to the vegetation. The three 
main belts of vegetation he characterized as Foothill, 
Timber and Arctic-alpine. The lecture was illustrated 
by many beautiful and instructive lantern slides. 
RUBBER IN RABBIT BRUSH 
Professor H. M. Hall lectured before the Society 
Feb. 8, on native sources of rubber with especial refer- 
ence to its occurrence in the genus Chrysothamnus. In 
1904 fragmentary samples of a desert shrub were sent 
in for identification from Inyo Co. The sender later 
suggested that this shrub might contain rubber, as the 
Indians had been observed chewing the twigs. In promot- 
ing his search for this shrub Dr. Hall made analyses of 
various desert shrubs and was finally guided to the par- 
ticular shrub sought by Indians near Benton, Mono Oo, 
This shrub was a form of Chrysothamnus nauseosus, the 
bark of which contains 4% rubber, sometimes as high 
as 6%. Rubber was also found in Chrysothamnus tereti- 
folius, Stenotus sp., and Ericameria ericoides of the 
coast sand dunes. 
