Solidago houghtonii Torr. & A. Gray
Common Name: HOUGHTON'S GOLDENROD
Coefficient of Conservatism: 10
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt P-Forb
Status: T
Solidago houghtonii B. S. Walters

Primarily in moist interdunal flats and hollows, with some plants on associated low dunes and beaches; nearby fens and swales; limestone crevices and pavements (alvars) on Drummond Island; often with S. ohioensis (which reaches peak flowering distinctly earlier), Lobelia kalmii, and other calciphiles. This very local species, listed as threatened under both Michigan and Federal law, occurs nowhere in the world except along the northern shores of Lakes Michigan and Huron. It is very nearly endemic to Michigan.

Solidago houghtonii is a hexaploid (2n = 54), hypothesized to be derived from hybridization between S. ptarmicoides and either S. ohioensis or S. riddellii. The rays are a strong yellow and conspicuous, making this a handsome plant in bloom. Reports of S. houghtonii from inland sites in Michigan are based on diploid (and generally pale-rayed) hybrids or S. vossii.

This and four others, S. ohioensis, S. ptarmicoides, S. rigida, and S. vossii, are the “flat-topped” goldenrods, sometimes segregated as the genus Oligoneuron.

Locations

Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Emmet County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Presque Isle County
Schoolcraft County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 12, 2017. http://www.michiganflora.net/species.aspx?id=458.