Eutrochium Rafinesque

Remark The words or terms in red (actually dark orange) in the text are defined in a glossary.

july_27_08.gthmb can't be loaded. The Eutrochium genus is that of perennials native to North America. The genus has 5 species that are also all native to North America, and two species, Eutrochium fistulosum and Eutrochium maculatum (picture at right), the later one with three varieties, are found in Québec.

The plants belonging to the genus are from 30 cm to over 3 m high. Their stems are erect, generally unbranched, at times more or less purple. Their leaves are mostly cauline, mostly whorled and petiolate. Their flower heads are discoid with 5 to 6 series of phyllaries. They have from 4 to 20 florets with usually purplish or pinkish corollas with 5 lobes. The fruits are dark brown to yellowish cypselae with a persistent pappus. Their have 10 chromosomes.

The genus belongs to the Asteraceae family.


In Greek, ευ (eu) means well and τροchο (trokho) means wheel, the genus name alluding to the usually whorled leaves of the species, a bit as the rays of a wheel.