Non-native plant, low growing on gravel

I was wondering if you can identify this found in northwestern Ontario. Thanks.

 

Spergularia sp.
There are three similar species in Ontario: S. media, S. rubra, and S. salina.
S. salina has 1-5 stamens (check your original photograph if you can count them).
S. media and S. rubra have 6-10 stamens.
- S. media has fleshy leaves and thick stem (1-4 mm below)
- S. rubra has less fleshy leaves and thinner stem (0.3-1 mm at lower part)

 

Thanks so much