Notholithocarpus densiflorus

American tanoak is in the beech or Fagaceae family. It is a broadleaf tree native to the western United States.

It was recently moved into a new genus, Notholithocarpus, from Lithocarpus, having previously been called American stone oak (Lithocarpus densiflorus).

• Leaves are deciduous, alternate, 7–15 cm long, with toothed margins and a hard, leathery texture, persisting for three to four years. When young, they are covered in dense orange-brown scurfy hairs on both sides, but those on the upper surface soon wear off; those on the under surface persist longer but eventually wear off too.
• Seed is an acorn 2–3 cm long and 2 cm across, very similar to an oak acorn, but with a very hard, woody nut shell more like a hazel nut. The nut sits in a cup during its 18-month maturation; the outside surface of the cup is rough with short spines. The nuts are produced in clusters of a few together on a single stem.