Angie, in short, the answer is yes. I once dug out a hosta and had a small part of it come up from remaining root stock. In general, I guess it would be necessary for there to be a little bit of crown left, but hostas vary quite a bit in the way their roots work and it would be quite possible for enough to be left if an older hosta were dug out.Also, I notice that there was a small hosta growing under my rose plant in the front yard. I asked my neighbor about it, and she said there was a hosta plant in the front garden, however the previous owner dug it up. Can hosta grow from leftover roots, or was this from seedling that fall down from previous years?
( I will take a picture of this tiny little baby hosta tomorrow. )
OTOH, it is also possible that it could be a seedling. Maybe the neighbour has some idea what the hosta was like that was there. Assuming it was NOT green, if the new plant IS green it's likely to be a seedling. Not a definitive answer, I know, but I hope that helps.
Ann