Rubber and resin content of native and introduced plants of Canada
In 1942 and 1943 the Botany and Plant Pathology Division, Canada Department of Agriculture, undertook a general survey of native and introduced plants thought to be capable of yielding natural rubber. Wide publicity was responsible for an excellent response to the request for plant material and in 1942 over 1400 samples were collected from all parts of Canada. Species of certain generic groups including Apocynum, Asclepias, and Solidago, established in plots at Ottawa, provided an additional 400 samples in 1943. The present publication presents the results of analyses of rubber and resin contents of this plant material.