The pipevine swallowtail butterfly, Battus philenor, is a large iridescent blue black butterfly with small tails and orange spots. The caterpillars of this butterfly can be found on the pipevine, Aristolochia, from where it gets it's name. The pipevine is a toxic plant but the pipevine caterpillars benefit from the toxin by ingesting it and storing in in their bodies so they too are toxic throughout their lives. The larval caterpillars can be found on the underside of the leaves and usually hang out in groups for safety. If you poke one, you will notice that they also have yellow horns which will expand out of their head.
Our native pipevine, the Dutchman's pipe, Aristolochia tomentosa, is named for the pipe like flowers that appear in May through June. The blooms are small and concealed within the foliage so make sure to inspect your plant carefully. When the flower has been fertilized it expands into a large seed capsule filled with very orderly and tightly packed seeds. The pipevine is a woody vine that can easily overwhelm a trellis if it is not pruned. It also has the bad habit of popping up in other locations like many of our vines.
If you have a suitable location this vine is an excellent choice with it's lush growth. Put it somewhere that you visit often so you are sure to poke through the leaves to find the flowers in spring and caterpillars in summer. Bring a caterpillar inside and watch it turn into a butterfly with your children. The swallowtail butterflies will be easy to spot in your garden and you will have the satisfaction of knowing that you supported them throughout their life.
Our caterpillars seem to spend a lot of time on top of the leaves.