Fagaceae -- comments
Comments: Some claim that the family contains the most biomass of any dicot group, hinting at the dominance this group displays in many temperate and montane tropical habitats. The wood is extremely valuable as lumber, firewood, etc. Edible nuts come from Castanea, Fagus, and Quercus (if leached of tannins). Lithocarpus and some others are commercial sources of tannins.
The cupule, found subtending or enveloping the pistillate flower or flowers in all members of this family, is a very unique characteristic of this family. The latest theory is that this structure is a highly reduced branching system, and is all that remains of a much larger pistillate inflorescence.
Involucres are composed of bracts that are modified leaves (remember the family Asteraceae?). Because the “bracts” that subtend or surround the pistillate inflorescence in the Fagaceae are interpreted to be part of a reduced branching system, it is more accurate to call this structure a cupule.