Bistorta affinis is a mat forming perennial from the Himalayas, very robust and spreads vigorously. I'm sure it will tolerate some rudimentary propagation by division.

 I got a serrated knife then cut off sections of mat where it is spreading from a border onto paving stones. I placed them in another bed, pressed them into loose soil and watered them in.

 Bistorta affinis was previously known as Persicaria affinis and before that Polygonum affine; part of the Knotweed family of plants by any name.