Slide lecture by California art historian David Adams, Ph.D. The unique Swedish artist Hilma af Klint used a variety of plant-related symbols in her celebrated abstract, spiritually inspired paintings. Some of these have complex histories in the development of esoteric traditions, such as her exhibited Tree of Knowledge series, while others, especially from the 1920s, are completely original and based on her own meditative practice or her own clairvoyant spiritual-scientific research, such as her three visual notebooks of research into the spiritual, emotional, and therapeutic qualities of many species of plants, on exhibit at Lightforms.