Sagina japonica is known from northern Ohio and southern Ontario (Rabeler 1996) and likely will be found in Michigan. It resembles S. procumbens somewhat, but is an annual with mostly 5-merous flowers and conspicuous glandular pubescence on the pedicels and upper stem.
1. Petals conspicuously exceeding the sepals; styles ca. 1–1.5 mm long.
1. Petals much shorter than the sepals, very inconspicuous; styles less than 0.5 mm long.
All species found in Sagina
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. June 21, 2018. https://www.michiganflora.net/genus.aspx?id=Sagina.