Beech cupules. The husk can have a variety of spine- to scale-like appendages, the character of which is, in addition to leaf shape, one of the primary ways beeches are differentiated. The nuts are edible, though bitter (though not nearly as bitter as acorns) with a high tannin content, and are called beechnuts or beechmast. The name of the tree (Latin "fagus", whence the species name; cognate with English "beech") is of Indo-European origin, and played an important role in early debates on the geographical origins of the Indo-European people. Greek φηγός is from the same root, but the word was
Beech bark disease Beech bark disease Beech bark disease is a disease that causes mortality and defects in beech trees in the eastern United States and Europe. In North America, the disease occurs after extensive bark invasion by the beech scale insect, "Cryptococcus fagisuga". Through a presently unknown mechanism, excessive feeding by this insect causes two different fungi ("Neonectria faginata" (previously "Nectria coccinea var. faginata") and "Neonectria ditissima" (previously "Nectria galligena")) to produce annual cankers on the bark of the tree. The continuous formation of lesions around the tree eventually girdles it, resulting in canopy death. In Europe, "N. coccinea" is the primary