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Aristolochia spp.

pipevines and birthworts

Aristolochiaceae

Pantropical and warm-temperate; Americas, Asia, Africa, and Europe

Attracts Pollinators Attracts Butterflies Deer Resistant

Native to North America

SunFull Sun – Part Shade

WaterMedium

HardinessZones 4–11

Overview

Aristolochia spp. is a large genus of roughly 400 to 500 species of climbing vines and herbaceous perennials in the family Aristolochiaceae, distributed across tropical and warm-temperate regions worldwide. Climbing species twine to 3-10 m (10-33 ft), while herbaceous species form clumps 0.3-1 m (1-3.3 ft) tall. The leaves are usually heart-shaped and 5-30 cm (2-12 in) long. The flowers give the genus its character: a curved, tubular perianth shaped like a pipe or siphon, often swollen at the base into a chamber and flared into a mottled purple-brown, maroon, or yellow-green limb at the mouth. These flowers briefly trap small flies, which pollinate them before being released. Flower size ranges from under 2 cm (0.8 in) in temperate species to more than 30 cm (12 in) in tropical A. gigantea. The fruit is a ribbed capsule that splits to release flat, stacked seeds. Aristolochia spp. foliage is the larval food of swallowtail butterflies in the genus Battus spp.. All parts contain aristolochic acid, a compound linked to kidney damage and urinary-tract cancers in humans, which limits any culinary or medicinal use.

Native Range

Native across tropical and warm-temperate parts of the Americas, Asia, Africa, and Europe. The genus reaches its greatest diversity in tropical Central and South America and in eastern Asia, with several species, including A. macrophylla and A. tomentosa, native to eastern North America.

Suggested Uses

Climbing species are grown on arbours, fences, and pergolas for dense summer screening and as larval host plants for swallowtail butterflies. Herbaceous species are used in woodland and shade borders. The large-leaved vines create quick seasonal cover on vertical structures.

How to Identify

Identified by heart-shaped leaves on twining stems and by the curved, pipe-shaped flowers with an inflated basal chamber and a flared, often mottled limb. The flowers lack true petals, the colour and form coming from the calyx. The ribbed, lantern-like seed capsule and the pungent smell of crushed stems further mark the genus.

Appearance

Size & Dimensions

Height1' - 33'

Width/Spread3' - 10'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

Spring Summer

Bloom time varies widely with climate. Temperate species such as A. macrophylla flower in late spring to early summer, roughly May to June, with the small flowers often hidden beneath the foliage. Tropical species can flower over many months or year-round. Individual flowers last only a few days while they complete their fly-pollination cycle.

Detailed Descriptions

Flower Description

maroon, purple-brown, or yellow-green

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam

Drainagewell drained

Water & Climate

Water Needs

Medium

Time to Maturity

2-3 years

Care & Maintenance

Care Guide

Most Aristolochia spp. grow in full sun to partial shade in moist, fertile, free-draining soil with steady summer moisture. Climbing species need a trellis, arbour, or other support and can be cut back hard in late winter to control their spread. Hardy species tolerate temperate winters once established, while tropical species need frost-free conditions or greenhouse protection. Propagation is from seed sown fresh or from softwood cuttings and division of rhizomatous types. The vines are vigorous and can overwhelm small supports within a season. All parts are toxic if eaten, containing aristolochic acid.

Pruning

Climbing species are cut back in late winter or early spring before growth resumes, removing weak and tangled stems and shortening the framework to fit its support. Herbaceous species die back to the ground and are cleared of dead stems in autumn or late winter. Hard renewal pruning is tolerated by most vining species.