Fossil leaves of Banksia, Banksieae and pretenders: resolving the fossil genus Banksieaephyllum

The genus <i>Banksieaephyllum</i>, originally erected for cuticle-bearing fossil leaves of subtribe Banksiinae (Proteaceae subfamily Grevilleoideae, tribe Banksieae), is reassessed. Of the 18 described species, nine are accepted within <i>Banksia</i>, including <i>Banksieaephyllum obovatum</i> Cookson & Duigan, which is synonymised with <i>B. laeve</i> Cookson & Duigan on the basis of new cuticular preparations. Two other species are transferred to <i>Banksieaefolia gen. nov</i>., a genus erected for Banksieae of uncertain affinities, and which presently includes only fossils that probably belong to subtribe Musgraveinae. The seven other <i>Banksieaephyllum</i> species lack definitive characters of Proteaceae (i.e. brachyparacytic stomata and annular trichome bases) and do not have Banksieae-type cylindrical trichome bases. These species are, therefore, not accepted as Proteaceae and are transferred to <i>Pseudobanksia gen. nov</i>., together with another fossil <i>Banksia</i>-like leaf species, <i>Phyllites yallournensis</i> Cookson & Duigan. Lectotypes are chosen for <i>Banksia fastigata</i> H.Deane, <i>Banksieaephyllum acuminatum</i> Cookson & Duigan, <i>Banksieaephyllum angustum</i> Cookson & Duigan and <i>Banksieaephyllum laeve</i> Cookson & Duigan. Implications arising from the re-assessment of <i>Banksieaephyllum</i> include clarification of biome conservatism in Banksieae; <i>Banksia</i> has long had an association with relatively open, sclerophyllous vegetation, and Musgraveinae with rainforest. <i>Pseudobanksia</i> and <i>Banksia</i> share convergent traits, but in contrast to <i>Banksia</i>, <i>Pseudobanksia</i> failed to survive the drying climates and increased fire-frequencies of the Neogene.