Thanks. I guess it comes from the name of the person, Alma Krossa, who imported it from Japan and introduced it. I don't know of many plants named in this way.
Lots of plants are names after people. I've got Eleanor Lachman. Here are just a few listed in a discussion on the old Hallson forums. The forums are pretty quiet these days, but the information is still there.
Frances Williams (hosta person)
Olive Bailey Langdon (hosta person)
Allan P. McConnell (hosta person)
Alex Summers (hosta person)
Gene Summers (hosta person's wife)
Jim Hawes (hosta person)
Mildred Seaver (hosta person)
Betsy King (hosta person? I only know the hosta)
Katie Q (Mark Zilis's wife)
Ann Kulpa (hosta person John Kulpa's wife/mother?)
Emily Dickinson (poet) (and of course her brother/sibling hosta Austin Dickinson)