Aloe haworthioides was described by Baker in 1887, moved to a unispecies genus Aloinella by Lemée in 1939 and then into Lemeea by Heath in 1993.  This was wisely all undone by G. F Smith et al in 1995.  This taxonomic dance is one of those events which probably bring taxonomy into disrepute in the minds of people otherwise respectful of scientific process.