We have a pretty common California weed in our yard. When we dig in the ground, we often find small ones there, with green leaves! It's as if they form green leaves before they come to the surface. While that seems counterintuitive, there's no purpose in having green beneath the soil, it doesn't seem impossible.
We had our yard redone 6 months ago. It's possible that some mature plants were buried- but would they stay green for six months? Or perhaps they expect to be close to the surface, so after creating a couple inches of roots, they form green leaves, even though they're buried deep enough that they're not at the surface yet.
Is this a known phenomenon? How common is it for plants to be able to make green leaves before coming to the surface?