Russula in my backyard

This photo and the following two are of a mushroom I found in my backyard. It's a Russula sp. How do I know? Well, for one, the bright white gills which reflect the white spore print. Okay, that's not a great character because gill color often doesn't betray spore print color. But the next clue is the crisp break in the stalk. This is a giveaway for the Russulaceae, and is caused by distinctive boxy shaped cells called sphaerocysts. The two main genera in the Russulaceae are Russula and Lactarius. Lactarius spp, as the name suggests, exude a milky secretion when the cap or stem are broken. So that leaves us with Russula. Which Russula? I don't know. There are no distinctively green capped Russula spp. in Bessette et al. Some Russulaceae are edible and choice, others not so much and could hurt you.