Quercus macrocalyx
Quercus macrocalyx is a tree species in the beech family Fagaceae There are no known subspecies. It is placed in subgenus Cerris, Quercus [sect. Cyclobalanopsis|section Cyclobalanopsis].
This oak tree grows up to 20 m tall and has been recorded from Vietnam, where it may be called sồi đấu to.