Eupatorium (Bonesets, Thoroughworts, Snakeroots, Hemp Agrimony) is a genus of perennial flowering plants in the family Asteraceae, comprising 36 - 60 species, depending on the classification system. It is native to temperate regions of the Northern Hemisphere.
Eupatorium purpureum (Sweet Joe Pye Weed, Trumpet Weed), 2.1 x 1 m, is a herbaceous perennial plant native to eastern and central North America. It is suitable to plant in mixed borders and has large, rough, mid-green leaves which are borne on stems that are upright, thick, round and purplish in color. From midsummer to early autumn, clusters of cream-white, pink, or pink-purple flowers are borne and attract butterflies and bees that feed on the nectar produced by the flowers.
Eupatorium cannabinum (Hemp Agrimony) is a robust, herbaceous perennial plant native to many areas in Europe. It is the only species native to Europe, with the remainder in Asia or North America. This plant can grow to about 1.5 x 1.2 m, in moist low-lying areas in temperate Eurasia. It is a dioecious, has red-tinged stems and large, dark green leaves. In summer to early autumn, flowers are borne in clusters of pink, purple or white color.
The smaller Eupatorium album (White Thoroughwort), 0.5 - 1 m, is native to the eastern states of the USA. Like other species in the genus, it also bears clusters of small white flowers in late summer. Its flower heads have disc florets but no ray florets.
Eupatorium grows well in sun or partial shade, in moisture-retentive and well-drained soil. Propagation is by seed in spring; divide in spring; and softwood cuttings in spring. Aphids, slugs and snails are pests that affecting this genus.
Eupatorium purpureum http://commons.wikimedia.org/wiki/File:Eupatorium_purpureum1.jpg Kurt Stüber