From Gerhard Marx:
The Japanese H. splendens hybrid ‘Shikinjo’ (also sometimes spelled
‘Shikinjoh’ and meaning ‘Forbidden City’) is a very attractively mottled
plant and when crossed with other H. splendens hybrids, some very good
‘Bob Barth’ was the combination of Shikinjo with H.
splendens X H. ‘Black Knight’. It was named in honor of Bob Barth from
Austin Texas, a sincere Haworthia enthusiast and noble friend.