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
English Lowlands beech forests include the Devil's bolete and hedgehog mushroom. At the end of the last glaciation, about 10,000 years ago, the area's ecosystem was characterised by a largely treeless tundra. Pollen studies have shown that this was replaced by a taiga of birch, and then pine, before their replacement in turn (c. 4500 BC) by most of the species of tree encountered today - including, by 4000 BC, the beech, which seems to have been introduced from mainland Europe. This was used as a source of flour, ground from the triangular nutlets contained in the "mast", or fruit of the beech, after