A vine that, over several years, may create a dense, tangled mat
of stems and leaves on open ground.
Cold deciduous. Stems and leaves die in freezes.
Vines up to 3' long form a dense green or purple-tinged
brown mat, of stems and leaves, 1-2' wide and 1" high.
Tiny, mouse-ear-shaped, green and brown flowers. Each flower
lasts one or two days. The flowers give off an aroma like that of a rodent's ear.
This attracts blood-sucking flies, which normally feed on the inside of rodent ears,
and forces them to become pollinators.
Spring and summer.
A capsule with five vertical ribs containing stacks of flat, black,
triangular seeds in five compartments.
Small, green, usually slender, arrowhead shaped leaves,
1-1.5" long, which turn purple-brown in full sun and drought conditions.
A food plant of the
caterpillar which incorporates the plant's poison into its skin to ward off
predators. This caterpillar can completely defoliate the plant, but the leaves will
Toxic / Danger:
All parts of this plant are toxic.
Native to Arizona, New Mexico and Mexico.
Cultivation and Uses
USDA hardiness zones: 8-9, possibly greater.
Heat tolerant: Yes.
Drought tolerant: Yes.
Sun: Best in part shade, but tolerates full sun.
Water once established: Once every month or two. Supplemental water may
improve growth. Soil should dry out between waterings.
Soil: Dry, low organic content, pH 6.6-7.5 (neutral).
Prune: Brush away dead leaves and stems after prolonged freeze.
Uses: To attract and propagate the Pipevine Swallowtail butterfly.
This plant is difficult to spot on open ground because of its small size.
Follow the Pipevine Swallowtail butterfly to locate the plant.
The third picture from the top is an Aristolochia watsonii mat, 16x12",
on an east-facing slope. The slope attenuates the afternoon sun and allows
the mat to stay green.
The bottom picture is a healthy, 2' wide, Aristolochia watsonii mat in full sun
and drought conditions on level ground. The root system is at least 8 years old.
This plant, and the plant in the picture above, are 50' apart, sharing the same
temperature and rainfall conditions.
These plants have become large because nearby lizards routinely search them
for butterfly eggs and small caterpillars. The caterpillars are never allowed
to get large enough to eat the whole plant and slow its root growth.
All photos taken in USDA hardiness zone 8b.
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