Sparganium angustifolium Michx.
Coefficient of Conservatism: 10
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt P-Forb

Sparganium angustifolium M. R. Penskar

In shallow quiet water at depths up to 1.5 m, rarely stranded on adjacent shores.

Normally easily recognized by the long, very narrow floating leaves (usually 2–3 mm wide, occasionally as wide as 5 mm or sheathing portions at base of plant even wider), and small supra-axillary heads of shiny, usually greenish achenes. The sepals are attached near the base of the stalk, especially in a low, semi-terrestrial form with rather curved beaks, which will run in most keys to S. fluctuans because of these characters. It differs from the latter species in its very narrow leaves, shiny, light brown to green, slightly smaller achenes, long sepals, supra-axillary heads, and unbranched inflorescence.


Alger County
Charlevoix County
    Including Beaver Island
Cheboygan County
Chippewa County
Clare County
Crawford County
Dickinson County
Emmet County
Gogebic County
Houghton County
Iron County
Isabella County
Kalkaska County
Keweenaw County
    Including Isle Royale
Leelanau County
    Including Fox Islands
Marquette County
Ogemaw County
Otsego County
Presque Isle County
Schoolcraft County
Wexford County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. June 27, 2022.