This taxon name is not current. The available references for this name are:
Phebalium ambiguum C.A.Gardner is more recently known as Microcybe ambigua (C.A.Gardner) Paul G.Wilson
Reason See Paul G. Wilson in Fl. Australia 26:484 (2013)
See also: A longer explanation of these and other terms in our Plant Names Primer.
A taxon name that is no longer current will retain its ‘Threatened’, ‘Extinct’, or ‘Extinct in the Wild’ status until a new name has been published in a Biodiversity Conservation Order.