There are 4 species included in this genus which is
native to Japan, Korea, China and other parts of
Asia.
It was named by
Asa Gray in honor of U.S. Admiral,
John Rodgers.
These
herbaceous perennials add a
moderately coarse texture to the design so they work well as a
transition plant in hosta gardens. Many of the species have
attractive flowers which are also noted for their pleasant
fragrance.