Erigeron decumbens is a species of flowering plant in the family Asteraceae known by the common names Willamette fleabane or Willamette daisy. It is native to Oregon and California in the United States.
The taxonomy of the plant varies by author. It may be treated as a species with two varieties,Erigeron decumbens. ITIS. the Californian variety var. robustiorErigeron decumbens. Jepson Manual Treatment. and the rare and endangered Oregon variety, var. decumbens.USFWS. Erigeron decumbens var. decumbens Five-year Review. September 2010. Alternately, the rare var. decumbens may be the only variety included within the species description and so named Erigeron decumbens,Erigeron decumbens. Flora of North America. with var. robustior separated and named Erigeron robustior.Erigeron robustior. Flora of North America.
The Oregon plant, var. decumbens or alternately Erigeron decumbens, is a federally listed endangered species of the United States. There are 28 occurrences growing in increasingly rare prairie habitat in the Willamette Valley.var. decumbens. Center for Plant Conservation.
The plant is a perennial herb growing up to about half a meter long, and erect or decumbent in form. The Oregon plant is colonial with a branching caudex sending up several stems, and is severely threatened. The inflorescence may contain many flower heads with white or blue-tinged ray florets that may dry pinkish. The California plant is not colonial and the caudex branches little or not at all. The inflorescence contains no more than 3 heads. The florets are white or pink-tinged.
References
External links USDA Plants Profile