H.P.Linder & C.R.Hardy (Cherm.) 2010 - Linder HP, Hardy CR (2010) A generic classification of the Restioneae (Restionaceae), southern Africa. Bothalia 40: 1-36. doi: 10.4102/abc.v40i1.178.
There is no corrections for Platycaulos mahonii subsp. humbertii yet.