Actually, they look rather like peonies. What's your location, the microenvironment, and the other plants in the yard other than grass? Peonies will grow in grass no problem; if that's what they are they're fairly young or the remains after someone divided the plants and took out the bigger half. But there are dozens of things with similar appearance in photos. It's hard to tell without scale, climate, or relative location, not to mention taste and smell, appearance in four seasons and a look at the
roots.
Lack of flowers is no indication, although of
course peony flowers ARE immediately distinctive. Given the appearance of barren, compacted earth in their vicinity, these would be quite within their rights to sulk and not flower for years, though.