Grevillea merceri Olde & Marriott (Proteaceae: Grevilleoideae: Hakeinae) an uncommon, geographically isolated species in the Triloba Group from subcoastal areas of southern Western Australia

The existence of Grevillea merceri Olde & Marriott, herein described, was brought to light following a single collection by the late Ken Newbey in 1963. His specimen was treated by McGillivray and Makinson (1993: 187) as ‘unassignable to species’ but with possible affinity to G. paniculata Meisn., a species very broadly conceptualised in their work. Revision and a more restricted delimitation of G. paniculata by Olde & Marriott (1994, 1995) clarified the many significant differences from this specimen. The relationship of G. merceri to other members of the Triloba Group however remains uncertain and awaits phylogenetic analysis.