Triosteum aurantiacum E. P. Bicknell
Common Name: HORSE-GENTIAN
Coefficient of Conservatism: 5
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Nt P-Forb

In diverse habitats, from swamps and rich deciduous forests to dry sandy or rocky forests with oak, aspen, sassafras, and/or pines, often at the edges.

Some authors treat this species as T. perfoliatum var. aurantiacum (E. P. Bicknell) Wiegand. A few specimens have styles clearly exserted (as much as 2 mm), but the leaf bases and stem pubescence are like those of T. aurantiacum. Pubescence characters are not as consistent as some keys suggest, but if many of the stem hairs are long and eglandular or if the pubescence is sparse, a specimen is pretty surely T. aurantiacum. If the hairs are dense, all or almost all short and mostly glandular, it is probably T. perfoliatum. Stems with short rather dense glandular hairs and a goodly number of longer hairs apparently occur in both species, especially on the distal internodes.

Locations

Alger County
Allegan County
Alpena County
Antrim County
Arenac County
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Calhoun County
Charlevoix County
Cheboygan County
Chippewa County
Clare County
Clinton County
Delta County
Eaton County
Gogebic County
Grand Traverse County
Gratiot County
Hillsdale County
Ingham County
Ionia County
Isabella County
Jackson County
Kalamazoo County
Kent County
Lake County
Lapeer County
Leelanau County
Lenawee County
Livingston County
Macomb County
Mecosta County
Midland County
Missaukee County
Monroe County
Montcalm County
Muskegon County
Newaygo County
Oakland County
Ontonagon County
Osceola County
Oscoda County
Ottawa County
St. Clair County
Van Buren County
Washtenaw County
Wayne County
Wexford County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 15, 2017. http://www.michiganflora.net/species.aspx?id=734.