2017 Plant of the Year, Special Recognition

Proposed by: a member of Orinda Garden Club, Zone XII

Endemic to northern California and native to the Sacramento Valley, San Francisco Bay area, Sierra Nevada foothills, USDA Zones 8 to 10, Aristolochia californica, commonly known as the California pipevine or California Dutchman’s pipe, is the exclusive food source for the larvae of the California pipevine swallowtail butterfly, Battus philenor hirsute. The red-spotted caterpillars eat the leaves of the pipevine and then use the flowers as a secure enclosure to undergo their transformation from larvae to butterfly. The leaves of the plant contain a toxin, which when eaten by the caterpillars, makes them unpalatable to predators.

 A deciduous woody vine, pipevine grows from rhizomes to a length of about 5 feet but can reach over 20 feet. The vine prefers part-shade and regular watering but can tolerate some drought. Common in moist woods and along streams in northern and central California, pipevine will spread out over open ground in the wild but can be trained on trellises or along paths in a garden providing a groundcover. The plant produces large green to pale brown, unpleasant, musty smelling pipe shaped blooms January through April that attract tiny carrion feeding insects that aid in pollination.  After the blooms, the vine sends out green heart shaped leaves. The leaves tend to dry and hang on the vine in the winter so it is suggested, in some sources, that one plants the pipevine with other plants. 

Photograph courtesy of UC Botanical Garden at Berkeley