Answer: hornbeam

AnswerCrossword Clue
HORNBEAMTree housing Arthur?
HORNBEAMBirch family member
hornbeamany North American shrub or tree belonging to the genus Carpinus, of the birch family, yielding a hard, heavy wood, as C. caroliniana(American hornbeam)
hornbeama small hardwood tree, also HARDBEAM