Aristolochia californica, the California pipevine, California Dutchman's-pipe, or California snakeroot is a perennial woody vine of western North America. Distribution and habitat The vine is endemic to northern California. It is native to the Sacramento Valley, northern Sierra Nevada foothills, San Francisco Bay Area, Northern Inner California Coast Ranges, southeastern Klamath Mountains. The plant grows along riparian streambank areas, in chaparral, oak woodland, and mixed evergreen forest habitats. It is found below in elevation. Description Aristolochia californica is a deciduous vine. It grows from rhizomes, to a length usually around , but can reach over . The twining trunk can become quite thick in circumference at maturity. It sends out new green heart-shaped leaves after it blooms. The bloom period is January through April. The plant produces large green to pale brown curving pipe-shaped flowers, with purple veins and a yellow to red lining. The U shaped flowers produce winged capsular green fruits. Pollination The California pipevine's flowers have a musty unpleasant odor which is attractive to tiny carrion-feeding insects. The insects crawl into the convoluted flowers and often become stuck and disoriented for some time, picking up pollen as they wander. Most eventually escape. The plant is not insectivorous, as was formerly thought. Fungus gnats (Mycetophilidae) may prove to be the effective pollinators. G.L. Stebbins suggested that pollination by deceit is presumed. Chemistry Like the other members of the family Aristolochiaceae, A. californica is highly toxic, producing a group of secondary metabolites known as aristolochic acids. Aristolochic acids are compounds that are composed of nitrophenanthrene carboxylic acids that have been utilized for medicinal purposes, being used in Chinese herbal medicines and usually included as a part of some weight-loss regimens. However, due to several warnings of the toxic effects of aristolochic acids by the US Food and Drug Administration and regulatory authorities of other countries, the sale and usage of aristolochic acids in medicine has been banned in multiple countries. The reasoning for this is that aristolochic acids act as a carcinogen and a nephrotoxin, inducing urothelial cancers and kidney failure. It has also been found that it may even act as a mutagen. California Pipevine Swallowtail Butterfly The larva of the endemic California pipevine swallowtail butterfly (Battus philenor hirsuta) relies on the California pipevine as its only food source. The red-spotted black caterpillars consume the leaves of the plants, and then use the flowers as a secure, enclosed