Marin Chapter California Native Plant Society


Aristolochia californica

PIPEVINE FLOWERS
photo by Mary Aline Stevens PIPEVINE FRUIT
and CATERPILLAR
photo by Mary Aline Stevens

Aristolochia californica, the California Pipevine, is a member of what may be one of the earliest groups of plants, the paleoherbs. The flower is composed of sepals fused into a calyx tube shaped like a calabash pipe. Before the leaves appear, the flowers form as miniature "pipes" only a fraction of a centimeter long. They continue to grow larger until reaching a final size of 2 to 4 centimeters. Thus you might notice flowers of different sizes on the same plant, as in the picture to the left. It is unusual to see flowers "grow up" in this way. In most other kinds of wildflowers, the showy part of the flower consists of petals that have reached their full size before emerging from their enclosing sepals. The fruit of the pipevine is a 6-winged capsule 2-1/2 to 6 centimeters in length.

Pollination of the California Pipevine

The pipevine flower produces a foul odor which attracts fungus gnats. Once they enter the flower through the "bowl" of the pipe, the fungus gnats are trapped inside for a long enough time to increase the chance of pollination. This has led to the misconception that the Pipevine is an insectivorous plant.

The Pipevine Swallowtail Butterfly and Caterpillar

PIPEVINE SWALLOWTAIL EGGS
photo by Mary Aline StevensPIPEVINE SWALLOWTAIL CATERPILLAR
photo by Mary Aline Stevens

The Pipevine Swallowtail butterfly lays its eggs exclusively on Aristolochia species. The larval stage, or caterpillar, uses this plant for food. The Pipevine contains a toxic chemical which is ingested by the Pipevine Swallowtail caterpillar, rendering it and the subsequent butterfly unpalatable to birds. When you find a Pipevine in leaf, look for small reddish eggs or, later, black caterpillars methodically munching away on the leaves. Young caterpillars will be quite tiny, so look closely. Caterpillars also relish the fruit of the Pipevine as can be seen in the photograph of the fruit (above).

PIPEVINE SWALLOWTAIL
BUTTERFLIES MATING
photo by Charles Kennard

Where to see California Pipevine in Marin County

California Pipevine can be seen just inside the entrance to Samuel P. Taylor State Park, growing on the trees and shrubs just to the right after you pass the entrance kiosk. Another good place to see it is Cascade Canyon Open Space in Fairfax. In April watch for Pipevine Swallowtail Butterflies. If you see a number of these butterflies, it is quite likely that California Pipevine is growing in the vicinity. While Pipevine Swallowtail Butterflies sip the nectar of other flowers, they will lay their eggs only on this plant. California Pipevine is widely distributed in Marin County. The first specimen of this species of Aristolochia to be described was found by the botanist John Milton Bigelow in Corte Madera, Marin County.


Distribution:

Aristolochia californica grows in California along streamsides and in low wooded hills. It is found in the Coast Ranges from Monterey County north to Mt. Shasta, in the Sacramento Valley, and in the northern Sierra Nevada foothills.

In the Marin Flora, John Thomas Howell lists its locations as Angel Island; Sausalito Hills; Phoenix Lake and Bootjack, Mt. Tamalpais; Fairfax Hills; San Rafael; Lagunitas Creek.
In A Flora of Sonoma County, Catherine Best et al. list its locations as Neeley Hill area near Guerneville; Forest Hills 5-1/2 mi e. of Guerneville; Russian River opposite Vacation Beach; Bouverie; Sonoma Cr. at base of Mt. Hood; Sugarloaf Ridge; Santa Rosa; Leslie Road near Mark West Springs; Pepperwood; Healdsburg quad.
In the Flora of the Santa Cruz Mountains of California, John Hunter Thomas lists its locations as "known definitely from Lake Merced in San Francisco and reported from other parts of the Santa Cruz Mountains."

You can view a distribution map like the one shown here for any plant included in The Jepson Manual by going to the web site maintained by the Jepson Herbarium.


Related Sites:

The University of California Museum of Paleontology has a discussion of Aristolochiales and paleoherbs.

Call of the Wild: The Creeks of San Anselmo by Charles Kennard, whose photograph of mating Pipevine Swallowtail Butterflies is shown above.

Northern Prairie Wildlife Research Center, USGS, Montana State University Big Sky Institute - Butterflies and Moths of North America : Pipevine Swallowtail Butterfly

PIPEVINE SWALLOWTAIL CATERPILLAR
photo by Mary Aline Stevens

Top of Page

Marin CNPS Home Page

Contact Marin CNPS at: carnelian@pacbell.net