https://en.wikipedia.org/wiki/Oxalis_acetosella

There's a type with has pale mauve/pink with dark lines that has bulbs, from which small clove like bits break of in the soil and reproduce invasively, maybe the seeds are also a viable source. They tend to have a single or a few stems. Another type has a yellow flowers a string like root with multiple stems and is half the size.

In two to three square metres I have dug up maybe four or five kilos.