[Wikipedia] Seed Details & Vigor, Toxin, Etymology: Arnica chamissonis has an active bloom period throughout the summer. There are approximately 400,000 seeds per pound. These individuals have a medium seedling vigor and a moderate vegetative spread rate. Seedling vigor refers to "the expected seedling survival percentage of the plant compared to other species with the same growth habit." A vegetative spread rate refers to how quickly a plant can spread through a given area. In general, A. chamissonis can be grown in a container, by using seeds or sprigs. Both A. montana and A. chamissonis contain the toxin helenalin. The species is named for German poet and botanist Adelbert von Chamisso, 1781 - 1838. (link added by Mary Ann Machi)