Zanthoxylum americanum Mill.
Common Name: PRICKLY-ASH
Coefficient of Conservatism: 3
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Nt Shrub

Sometimes in upland deciduous forests, but usually in moist forests and thickets, even swamps, along streams and river banks.

Like Ptelea trifoliata, this species has oils that have given it reputed medicinal properties. The plant is usually a tall shrub, and spreads readily by suckers, forming large, spiny thickets. Vegetative specimens might superficially resemble Robinia pseudoacacia in the spiny stems and pinnately compound usually sparsely pubescent leaves. In Zanthoxylum americanum, the leaflets are ovate, ± acute but notched at the tip with a gland but without a mucro, sessile or nearly so. In Robinia, the leaflets are more elliptic, rounded at the tip but with a small mucro (even if somewhat notched), each with a distinct petiolule-pulvinus.

The forma impuniens Fassett, entirely unarmed, has been collected in Eberwhite Woods, Ann Arbor (Washtenaw Co.)

 

Locations

Allegan County
Alpena County
Barry County
Bay County
Benzie County
Berrien County
Branch County
Calhoun County
Cass County
Cheboygan County
Clare County
Clinton County
Delta County
Dickinson County
Genesee County
Gladwin County
Gratiot County
Hillsdale County
Huron County
Ingham County
Ionia County
Isabella County
Jackson County
Kalamazoo County
Kalkaska County
Kent County
Lake County
Lapeer County
Lenawee County
Livingston County
Manistee County
Mason County
Mecosta County
Menominee County
Midland County
Missaukee County
Monroe County
Montcalm County
Muskegon County
Newaygo County
Oakland County
Osceola County
Oscoda County
Ottawa County
Saginaw County
Sanilac County
Shiawassee County
St. Clair County
St. Joseph County
Tuscola 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 11, 2017. http://www.michiganflora.net/species.aspx?id=2610.