Eutrochium purpureum


Eutrochium purpureum, commonly known as purple Joe-Pye weed, kidney-root, sweetscented joe pye weed, sweet Joe-Pye weed, is an herbaceous perennial plant in the sunflower family. It is native to eastern and central North America, from Ontario east to New Hampshire and south as far as Florida, Louisiana, and Oklahoma. It is sometimes called gravel root or trumpet weed.

Description

Eutrochium purpureum is a clump-forming herb that grows to tall and about wide. Plants are found in full sun to part shade in mesic to wet soils. Stems are upright, thick, round, and purple, with whorls of leaves at each node. As the plant begins to bloom the stems often bend downward under the weight of the flowers. The leaves grow to long and have a somewhat wrinkled texture. The purplish flowers are produced in large loose, convex shaped compound corymbiform arrays. Plants bloom mid to late summer and attract much activity from insects that feed on the nectar produced by the flowers.

Taxonomy

This species hybridizes readily with other species of Eutrochium and where this species and those species overlap in distribution the resulting plants can be difficult to resolve to a specific taxon. There are two varieties that differ in the pubescence of the stems and foliage, but many more have been proposed in the past, though most authorities now accept that this is a variable species and population variations integrate.

Ecology

Many species of butterflies, moths, bees, and flies visit the flowers.
It is larval host to the eupatorium borer moth, the red groundling moth, the ruby tiger moth, and the three-lined flower moth.
The larvae of Calycomyza flavinotum, a leaf miner fly, create blotch-shaped mines on the leaves.

Cultivation

Eutrochium purpureum is sometimes cultivated and has escaped from cultivation in parts of New Zealand.