What is this wierd stuff in the root?

Hi , i have a pot with a plant which i dont know.which plant it is.
I killed the plant because i want to use it the pot.for.planting another plant, when i take of the plant from the soil i.realized that the roots have some wierd  stuff like small.balloons. Do anybody know what.are.these ballons? Are they nitrogen fixer nodules? Ive seen before.nitrogen fixer nodules but they are.much smaller. Any idea.what are.these ballons and.which plant is it?

Looks like Asparagus Fern , which has tubers like that, but may not be edible.