The Euthamia Nuttall genus

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

aug_09_09.gthmb can't be loaded. Euthamia, the Grass-leaved Goldenrod, is a small genus of erect, herbaceous perennials native to North America. The genus has nine eastern species and one western species. The genus was incorrectly included in the Solidago genus by many authors for a more than a century although its morphology and leaf anatomy were quite apart form the other members of the genus. The plant belongs to the Asteraceae family.

Euthamia is still often listed in the Solidago genus; Euthamia returned 19 700 results on Google while Solidago returned 735 000 results!

Furthermore, cpDNA (chloroplast DNA) studies as well as cpDNA RFLP (Restriction Fragment Length Polymorphisms) studies, showed that Euthamia was phylogenetically not close to the true Goldenrods (Solidagos) with a number of other genera more closely related. These studies showed that the genus Solidago is related:

The Sericocarpus genus (the White-rayed Aster) is also related to the Solidago genus. But the Euthamia genus is not as closely related to the Solidago genus as these genera.

All species of Euthamias have erect stems bearing linear grass-like leaves with 1 to 7 well-developed veins and head borne in clusters. The genus includes the following species:


In Greek, the adverb ευ (eu) means well, regularly and θαμειοσ (thameios) means numerous, frequent, so that Euthamia would refer to the dense inflorescence of the genus.