Sawtooth Oak Identification: The "Mop-Head" Acorn Culprit

Oaks with bristly, "mop-head" acorn caps are likely sawtooth oak (Quercus acutissima), an Asian species planted for wildlife attraction. Unfortunately, these acorns sprout so aggressively the tree becomes invasive, crowding out native plants. Native chestnut oak would have been a more ecologically responsible choice for the school landscape.