Melilotus officinalis (L.) Pall.
Common Name: YELLOW SWEET-CLOVER
Coefficient of Conservatism: *
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Ad B-Forb

Melilotus officinalis B. S. Walters

Roadsides, fields, railroads, disturbed areas in forests, shores, disturbed places generally. Of similar status to M. albus, but only more recently becoming abundant, even though first collected in 1876 (in Shiawassee Co.).

This species begins to bloom several days earlier than M. albus. The only consistently reliable way to distinguish the two is by flower color. Some yellow is usually detectable even in old dry corollas of M. officinalis. The racemes in M. albus at peak of flowering are often much longer (8–15 times as long as wide) than in M. officinalis, where they are rarely more than 6 times as long as wide. In M. albus, the standard often distinctly exceeds the wings, while in M. officinalis it is usually about the same length, but there are many exceptions. The leaflets of M. officinalis tend to be broader, usually no more than about twice as long as broad, while in M. albus they are often narrower (ca. 2.5–3.5 times as long as broad).

Locations

Alcona County
Alger County
Allegan County
Alpena County
Arenac County
Baraga County
Barry County
Bay County
Benzie County
Berrien County
Calhoun County
Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Clare County
Clinton County
Crawford County
Dickinson County
Eaton County
Emmet County
Genesee County
Gladwin County
Grand Traverse County
Gratiot County
Hillsdale County
Houghton County
Ingham County
Ionia County
Isabella County
Jackson County
Kalamazoo County
Kent County
Keweenaw County
    Including Isle Royale
Lake County
Lapeer County
Leelanau County
    Including Manitou Islands
Lenawee County
Livingston County
Luce County
Mackinac County
    Including Bois Blanc, Mackinac, Round Islands
Macomb County
Manistee County
Marquette County
Mason County
Mecosta County
Midland County
Monroe County
Montcalm County
Montmorency County
Muskegon County
Newaygo County
Oakland County
Oceana County
Ogemaw County
Ontonagon County
Oscoda County
Otsego County
Ottawa County
Presque Isle County
Saginaw County
Sanilac County
Schoolcraft County
Shiawassee County
St. Clair County
Tuscola 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://michiganflora.net/species.aspx?id=1335.