Ammannia robusta Heer & Regel
Coefficient of Conservatism: 6
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt A-Forb

Ammannia robusta inflorescences in leaf axils A. A. Reznicek inflorescences in leaf axils

Marshy ground and muddy flats, especially disturbed areas with bare soil. Though treated as native, except for a 1914 collection from Detroit (Wayne Co.), this species was not collected in Michigan before 1972. It appears to be increasing in abundance.

Plants of this species and of Rotala are often strongly flushed with red. Petals in both are quickly deciduous, but are a little larger and showier in Ammannia than in Rotala.


Allegan County
Monroe County
Wayne County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. November 29, 2022.