New Banksieaeidites species and pollen morphology in Banksia

Cookson (1950) erected the fossil pollen genus Banksieaeidites to accommodate palynomorphs with characters resembling those of the extant Proteaceae genus Banksia. One of the most commonly reported species, Banksieaeidites arcuatus Stover& A.D.Partr., is now known to more closely resemble pollen of the Proteaceae subtribe Musgraveinae, than that of subtribe Banksiinae. The late Eocene Mulga Rock deposits in the southern Officer Basin of Western Australia have yielded palynofloras that contain up to 7% of two new species that can confidently be aligned with pollen of modern Banksia. Banksieaeidites davidsonii sp. nov. and B. rugulus sp. nov. are formally described, and pollen from eight extant Banksia are described and compared with the two fossil species. The variation in extant Banksia L.f. pollen morphology, and that between the two Banksia subgenera (B. subgenus Banksia and B. subgenus Spathulatae A.R. Mast & K.R. Thiele) are discussed, and the changes in the morphology of Banksia pollen grains as they mature are reported.