Hi,
Paris cronquistii has purple markings on the backside of the leaves, what gives a slightly marmorated aspect to them. It usually has a number of stamens three times the number of the petals and the free connective on top of the stamen is much shorter than the one the picture.
I'm almost certain that your plant is Paris thibetica. A species that easily forms colonies. The very long (sometimes 2 cm) free connective is typical for this species and also the black seed partly covered by a red aril.
Robin