Morphological analysis of the Grevillea ilicifolia complex (Proteaceae) and recognition of taxa

Abstract

A morphological study of herbarium and field-collected specimens, using phenetic techniques of agglomerative classification, ordination and minimum spanning trees, and covering the geographic range of the Holly Grevillea, G. ilicifolia (R.Br.) R.Br. sensu lato, has resulted in the recognition of three species and four subspecies. The taxa are based on leaf form, noted by previous authors to be highly variable between populations. The taxa recognised here are G. ilicifolia, G. ilicifolia subsp. ilicifolia (typical, kite-shaped leaf form), G. ilicifolia subsp. lobata (F.Muell.) T.L.Downing comb. et stat. nov. (oak-shaped leaf form), G. dilatata (R.Br.) T.L.Downing comb. et stat. nov. (fan-shaped leaf form), G. angustiloba (F.Muell.) T.L.Downing comb. et stat. nov., G. angustiloba subsp. angustiloba (narrow-lobed leaf form) and G. angustiloba subsp. wirregaensis T.L.Downing subsp. nov. (very narrow-lobed leaf form). The rank of subspecies is used where there are some intermediate plants between forms. Grevillea ilicifolia subsp. ilicifolia is the most widespread taxon and occurs in South Australia, western Victoria and in two localities in New South Wales. Grevillea angustiloba subsp. wirregaensis has the most restricted range, occurring in semi-arid regions near Wirrega in South Australia. Grevillea dilatata is largely endemic to Kangaroo Island, South Australia.