Apocynum cannabinum L.
Common Name: INDIAN-HEMP
Synonym: Apocynum sibiricum
Coefficient of Conservatism: 3
Coefficient of Wetness: 0
Wetness Index: FAC
Physiognomy: Nt P-Forb

Often in similar habitats to A. androsaemifolium, although more frequent on wet soils: shores, thickets, river banks, at least seasonally wet marshes and meadows; but also in disturbed ground, along railroads and highways, in fields.

Like A. androsaemifolium, variable especially in pubescence. Plants with leaf blades on the main stem ± tapered to distinct petioles are typical var. cannabinum. Plants with the main blades ± subcordate and sessile or nearly so are var. hypericifolium A. Gray [also known as A. sibiricum Jacq.] Plants with subcordate petiolate blades or otherwise intermediate between the alleged varieties support the skepticism with which they are now often viewed. The mature corolla is usually about twice as long as the calyx, or shorter, and the flowers are ± erect in terminal cymes (at ends of main stem and principal branches), rarely axillary. The seeds (excluding hairs) in A. androsaemifolium do not exceed 3 mm in length, while in A. cannabinum they are distinctly longer, ca. (3.2–) 3.5–5.5 mm.

Locations

Alcona County
Alpena County
Arenac County
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Branch County
Calhoun County
Cass County
Charlevoix County
Cheboygan County
Chippewa County
    Only on Drummond Island
Clare County
Clinton County
Delta County
Eaton County
Emmet County
Gogebic County
Grand Traverse County
Hillsdale County
Huron County
Ingham County
Ionia County
Iosco County
Isabella County
Jackson County
Kalamazoo County
Kent County
Lapeer County
Leelanau County
Lenawee County
Livingston County
Luce County
Mackinac County
    Only on Bois Blanc, Mackinac, Round Islands
Macomb County
Marquette County
Mason County
Mecosta County
Midland County
Monroe County
Montcalm County
Muskegon County
Newaygo County
Oakland County
Oceana County
Ontonagon County
Ottawa County
Presque Isle County
Saginaw County
Schoolcraft County
Shiawassee County
St. Clair County
St. Joseph County
Tuscola County
Van Buren County
Washtenaw County
Wayne 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=153.