Table of Contents for Western Goldentop (Euthamia occidentalis)
Western Goldentop (Euthamia occidentalis) is a herbaceous perennial that is native to the western United States and the province of British Columbia in Canada. This plant is a host to several moths and is important as a nectar source for bees and other insects. Growing from 1 to 7 feet tall, this species grows on the edges of wetlands in wet to moist soil. The yellow flowers bloom from July to November and the plant is hardy in zones 8-9.
Taxonomy and Naming of Western Goldentop (Euthamia occidentalis)
Western Goldentop (Euthamia occidentalis) was originally named and described by Thomas Nuttall, an American botanist in 1840. It still has the same name and is a member of the Aster Family (Asteraceae).
Meaning of the Scientific and Common Names
The genus name, Euthamia, is likely a composite name of the Greek words “thamees” crowded and “ia” to place (Merriam-Webster Dictionary). The species name, occidentalis, is Latin for “western” and refers to the distribution of the species.
Common Name and Alternative Names
The common name, like the species name, comes from the distribution of the plant. Other common names include western flat-topped goldenrod and western goldenrod.
- Plant Type: This plant is a herbaceous perennial.
- Height: 1 to 7 feet tall
- Stem: The stems are erect, branching, glabrous and glaucous. The roots are fibrous and spread by rhizomes (Sieren 1981).
- Leaves: The leaves are alternate, sessile, linear, have entire scabrous margins and are 3-5 nerved. They are 3 to 4 inches long and 0.1 to 0.4 inches wide.
- Flower color: yellow
- Blooming period: This plant blooms from July to November.
- Fruiting type and period: This plant has achenes that mature in the late fall and winter.
Range of Western Goldentop in the United States and Canada
This species is native to the western United States and the province of British Columbia in Canada. It is considered to be common throughout its range.
This species grows in wet to moist soil on the edges of wetlands such as pond margins, rivershores (House 1914 and Peck 1916), riparian shrubland (Heil 2013), vernal pools (Reifner and Pryor 1996), estuarine scrub/shrub wetlands and dune swales (Ferren 1990), high marsh (Ferren 1985 and Kelch and Murdock 2012), thickets (Gillett 1908), and roadsides and prairie margins (Christy, et al 2009).
The members of the goldentop genus (Euthamia) are hosts to many species of moths including Coleophora intermediella, Epiblema desertana, and Cucullia florea. This particular species has been noted as hosting the white-lined sphinx (Hyles lineata) (Calscape).
Other Supported Wildlife
This species is an important nectar source to other butterflies, skippers, bees, and wasps during fall season when a lot of other plants have finished flowering.
Frequently Asked Questions
Does this plant have any ethnobotanical uses?
The Native American Ethobotanical Database does not cite this species specifically, but a related species in the genus, Euthamia graminifolia, has been used for pain and lung issues.
How is this plant distinguished from other Goldentops?
This species is the only Euthamia in North America with glaucous stems and serves to identify it (Flora of North America).
How are Goldentops distinguished from Goldenrods?
At first glance this species looks similar to a goldenrod and has at times been placed in the goldenrod genus, Solidago (Nesom 1999). However, the goldentops, Euthamia, have flat-tops versus the non flat-topped goldenrods.
Is this plant invasive?
This plant has not been noted as being weedy.
Gardening with Western Goldentop
This species is hardy in zones 8-9. If your garden is within these zones and you have the right growing conditions (soil, moisture and exposure), you may well be able to grow this plant. However, if planted outside of its range, the hosted species may not recognize the plant or be harmed by ingesting a different species with an unfamiliar chemical composition.
This species grows in full sun and well-drained soil.
- Christy, John A., Angela Kimpo, Vernon Marttala, Philip K. Gaddis, and Nancy L. Christy. 2009. Urbanizing Flora of Portland Oregon, 1806-2008. Occasional Paper 3 of the Native Plant Society of Oregon.
- Ferren, Wayne R. 1990. Botanical resources at Emma Wood State Beach and the Ventura River Estuary, California: inventory and management: report to the State of California Department of Parks and Recreation. (Santa Barbara, CA: University of California) Environmental Report No. 15.
- Ferren, Wayne R. 1985. Carpinteria Salt Marsh: environment, history, and botanical resources of a Southern California estuary. (Santa Barbara, CA: University of California) Publication No. 4.
- Gillett, John M. 1908. Botanical Notes – Euthamia occidentalis. The Ottawa Naturalist 21: 231.
- Heil, Kenneth D., Steve O’Kane, Linda Mary Reeves, and Arnold Clifford. 2013. Flora of the Four Corners Region: Vascular Plants of the San Juan River Drainage. Monographs in Systematic Botany from the Missouri Botanical Garden v. 124.
- House, H.D. 1914. Vegetation of the Coos Bay Region, Oregon. Muhlenbergia 9: 99-152.
- Kelch, Dean G. and Andrew Murdock. 2012. Flora of the Carquinez Strait Region, Contra Costa and Solano Counties, California. Madrono 59: 47-108.
- Nesom, Guy. 1999. Review of the Early Nomenclature in Euthamia (Asteraceae: Astereae). Sida 18: 1009-1018.
- Peck, Morton E. 1916. A Section of Upper Sonoran Flora in Northern Oregon. Proceedings of the Iowa Academy of Science 23: 317-334.
- Reifner, Richard E. and David R. Pryor. 1996. New locations and interpretation of vernal pools in Southern California. Phytologia 80: 296-327.
- Sieren, D.J. 1981. The Taxonomy of the Genus Euthamia. Rhodora 83: 551-579.