The identification of fossil pollen at the generic rather than species level is hampering progress in understanding the biogeography and dynamics of paleo-vegetation. We used CART analysis to facilitate the differentiation of fossil pollen of Pinus banksiana and Pinusresinosa, which are morphologically similar and nearly always combined in paleoecological studies. The CART model, using four of the ten morphological traits measured, exhibited a high level of correct identification for pollen of each of the species and shows promise as a tool for increasing the detail of paleoecological records and inferences.