Rhus glabra L.
Common Name: SMOOTH SUMAC
Coefficient of Conservatism: 2
Coefficient of Wetness: 5
Wetness Index: UPL
Physiognomy: Nt Shrub

Rhus glabra stem A. A. Reznicek stem

Fields and clearings, roadsides, dry banks and hillsides, rocky slopes and summits, in open ground or open forests.

Notorious for hybridizing with R. typhina; presumed hybrids (R. ×pulvinata Greene) are more common in Michigan than pure R. glabra, and perhaps have a slightly wider distribution. The hybrids, and both parents, form large, uniform colonies from root suckers.

Hybrid variants may be conveniently sorted into the following four groups:

(1) New branches and petioles with dense hairs but few if any as long as in R. typhina; fruit (if present) with hairs shorter than in R. typhina, ± blunt or some of them clavate.

(2) New branches and petioles glabrous or nearly so but fruit with the characteristic long sharp-pointed hairs of R. typhina. [Vegetative or staminate specimens of such a variant would probably be referred to R. glabra by most observers].

(3) Hairs of fruit partly clavate and partly sharp-pointed, shorter than in R. typhina but often a bit long for R. glabra; pubescence of vegetative parts ranging from dense and long as in R. typhina to glabrous. These are among the commonest of the presumed hybrids, and the intermediate nature of the fruit pubescence is the most convincing evidence.

(4) Hairs of fruit as in R. glabra but pubescence of vegetative parts too abundant or long for that species. Such plants seem rare.

Locations

Allegan County
Arenac County
Baraga County
Berrien County
Branch County
Calhoun County
Charlevoix County
Cheboygan County
Dickinson County
Eaton County
Emmet County
Gratiot County
Hillsdale County
Houghton County
Ingham County
Jackson County
Kalamazoo County
Kent County
Keweenaw County
Leelanau County
Lenawee County
Livingston County
Mackinac County
    Only on Bois Blanc, Mackinac, Round Islands
Macomb County
Marquette County
Mecosta County
Monroe County
Montmorency County
Oakland County
Presque Isle County
St. Clair 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 13, 2017. http://michiganflora.net/species.aspx?id=96.