Fragaria

1. Mature fruiting receptacle ± conical, the achenes not sunken but projecting from the surface; calyx lobes widely spreading to reflexed from the developing fruit; terminal tooth of leaflets equaling or exceeding the adjacent pair of lateral teeth; hairs on peduncles and petioles usually ± appressed.

F. vesca

1. Mature fruiting receptacle ± ovoid to spherical, the achenes sunken in depressions; calyx lobes appressed to the developing fruit; terminal tooth of leaflets reduced, usually surpassed by the adjacent pair of lateral teeth and only half (or less) as broad; hairs on petioles (and, often, peduncles) ± strongly spreading.

F. virginiana

All species found in Fragaria

Fragaria vescaWOODLAND STRAWBERRY 
Fragaria virginianaWILD STRAWBERRY 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. August 18, 2017. http://michiganflora.net/genus.aspx?id=Fragaria.