Sorbus decora (Sarg.) C. K. Schneid.
Common Name: MOUNTAIN-ASH
Coefficient of Conservatism: 4
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Nt Tree

Forested dunes and bluffs, especially frequent at edges of forests along Lake Superior; deciduous, mixed, and coniferous forests, often with fir, cedar, and pine, but sometimes in beech-maple stands; seems to thrive particularly well along shores, perhaps because of the moister climate and perhaps because released from competition of larger trees in the forest.

A few unusually pubescent flowering specimens closely resemble S. aucuparia. There is a subtle distinction usually evident in the tips of the leaflets, where the terminal tooth is prolonged in S. decora (as in S. americana), whereas in S. aucuparia it is no more conspicuous than the lateral teeth (which are frequently partly doubly serrate). Sorbus decora varies considerably in overall shape of the apex of the leaflet and in pubescence. The dried fruit in herbarium specimens is often strikingly blue-glaucous. This is our commonest species of Sorbus, a handsome small tree when in flower (or fruit).

Locations

Alcona County
Alger County
Alpena County
Baraga County
Benzie County
Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
Delta County
Dickinson County
Emmet County
Gogebic County
Gratiot County
Houghton County
Iosco County
Isabella County
Kalamazoo County
Kent County
Keweenaw County
    Including Isle Royale
Leelanau County
    Including Fox Islands
    Including Manitou Islands
Luce County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Manistee County
Marquette County
Mason County
Montcalm County
Muskegon County
Oakland County
Ontonagon County
Ottawa County
Schoolcraft County
Wayne County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 17, 2017. http://www.michiganflora.net/species.aspx?id=2571.