Equisetum laevigatum A. Braun
Common Name: SMOOTH SCOURING RUSH
Coefficient of Conservatism: 2
Coefficient of Wetness: -3
Wetness Index: FACW
Physiognomy: Nt Fern Al

Equisetum laevigatum ex W. H. Wagner slide collection

Moist to dry sandy shores, low dunes, meadows, prairies, roadsides, railway embankments, ditches, also fens and open swamps; rarely in heavily shaded sites.

Plants keying here, but with persistent sheath teeth and stems narrower than usual are probably Equisetum ×nelsonii where the fact that the lower internodes are evergreen was overlooked.

Equisetum ×nelsonii is a common hybrid of E. laevigatum and E. variegatum, especially prevalent in disturbed areas with sandy soils, including naturally disturbed sites such as dunes, beaches, and shores as well as sites artificially disturbed such as borrow pits, road banks, and railway verges. As might be expected from a hybrid, presumably formed repeatedly many times, the appearance of the plant can be somewhat variable, often resembling somewhat robust E. variegatum but with smoother stem ridges, but sometimes robust and looking like a narrow-stemmed E. laevigatum with ± persistent sheath teeth. Plants keying to Equisetum ×nelsonii, but with a dark band at the base as well as at the apex of the lower sheaths are probably occasional small individuals of E. ×ferrissii, (see E. hyemale) which are, unfortunately, difficult to accommodate in the key.

 

Locations

Allegan County
Barry County
Berrien County
Calhoun County
Cheboygan County
Chippewa County
Clinton County
Emmet County
Gladwin County
Grand Traverse County
Hillsdale County
Houghton County
Iosco County
Jackson County
Kalamazoo County
Kent County
Keweenaw County
Lake County
Leelanau County
Lenawee County
Livingston County
Mackinac County
Macomb County
Mecosta County
Menominee County
Monroe County
Montcalm County
Montmorency County
Newaygo County
Oakland County
Roscommon County
Schoolcraft County
Shiawassee County
St. Clair County
St. Joseph 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 16, 2017. http://www.michiganflora.net/species.aspx?id=1200.