Remberella, a new genus of extinct ericalean flower from the Middle Miocene Latah flora of Washington and Idaho, USA

Small pentamerous floral remains commonly encountered in Middle Miocene lake deposits of the Latah Formation of Washington and Idaho, USA, previously assigned to Diospyros, are here shown to represent an extinct genus. Newly recovered specimens preserve characters of the androecium and pollen that were previously unknown. Remberella microcalyx (Knowlton) gen. et comb. nov. flowers are actinomorphic, with five basally connate petals having an adnate androecium including ten staminodes and ten stamens. The elongate-triangular anthers contain finely rugulate, triaperturate pollen. The combination of pentamerous sympetalous corolla, ten staminodes in two whorls and ten stamens adnate to the corolla indicates affinity with early divergent superasterids, likely the Ericales, with intriguing similarities to Ebenaceae. Although the Miocene flora includes many genera confidently assigned to extant genera, Remberella adds to a growing number of contemporary extinct genera.