I have always been under the assumption that there are two types of liriope.....muscari (the clumping type) and spicata (the spreading type.) I had one years ago that stayed in nice neat green clumps under a tree for years and every year I filled between with impations. The clumps got bigger but it did not send out runners or look weedy. It was a good, and easy look. The last few years when I spec. liriope muscari for a job and go back a year or two later it is spreading like a weed! Is there no true clumping form? Are nurseries mislabeling the varieties? Can anyone shed some light?