belonging to the Fagaceae, the beech family of plants.
Origin of fagaceous
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
of, relating to, or belonging to the Fagaceae, a family of trees, including beech, oak, and chestnut, whose fruit is partly or wholly enclosed in a husk (cupule)
Word Origin for fagaceous
C19: from New Latin Fāgāceae, from Latin fāgus beech
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012