The odd, pipe-shaped flowers of Dutchman’s pipe (Aristolochia macrophylla). Photo by Nancy Rose.
A pipevine swallowtail butterfly drinks nectar from smooth azalea (Rhododendron arborescens) flowers. Photo by Kyle Port.
is a genus composed of herbaceous perennials and twining vines [pdf]
, the latter commonly known as pipevine or birthwort. There are about 500 species worldwide, many of them tropical. The Arboretum has accessions of four temperate zone Aristolochia
species, two from North America and two from Asia.
Dutchman’s pipe (A. macrophylla) is a widely distributed North American species with a native range covering much of the eastern third of the U.S. plus southern Ontario. Its curious common name comes from the shape of the flowers, which look (with some imagination) like small meerschaum pipes. The flowers internal color pattern and smell attract flies that become temporarily trapped until they complete their pollination duties. Perhaps the most ornamentally notable feature of this species is its very large (up to nearly a foot long!), dark green, heart-shaped leaves, which can provide quick cover to chain link fences or shade a trellised porch.
A female pipevine swallowtail lays eggs on the stems of Dutchman’s pipe (Aristolochia macrophylla). Photo by Robert Mayer.
Humans may admire the leaves, but for pipevine swallowtail butterflies (Battus philenor
) those leaves are an essential food source. The females of this large and spectacular butterfly species lay eggs exclusively on Aristolochia
vines and the tiny newly hatched caterpillars chomp voraciously on the leaves, ingesting a toxic compound (aristolochic acid) that they can tolerate but which repels predators from eating them. Naturalist and longtime Arboretum volunteer Bob Mayer recently photographed a pipevine swallowtail butterfly and its caterpillars in action on the Dutchman’s pipe vines that cover the fence around the maintenance garage next to the Hunnewell building (Bob will be talking about this at a Tree Mob
on July 18, 5:00 p.m.). If you want to invite these beautiful butterflies to your yard consider planting a Dutchman’s pipe or other native Aristolochia
Nancy Rose, editor of Arnoldia