Notholithocarpus

Notholithocarpus densiflorus, commonly known as the tanoak or tanbark-oak, is an evergreen tree in the beech family (Fagaceae), native to the western United States, in California as far south as the Transverse Ranges, north to southwest Oregon, and east in the Sierra Nevada. It can reach 40 m (130 ft) tall (though 15–25 m (49–82 ft) is more usual) in the California Coast Ranges, and can have a trunk diameter of 60–190 cm (24–75 in).

Tanbark-oak was recently moved into a new genus, Notholithocarpus (from Lithocarpus), based on multiple lines of evidence. It is most closely related to the north temperate oaks, Quercus, and not as closely related to the Asian tropical stone oaks, Lithocarpus (where it was previously placed), but instead is an example of convergent morphological evolution.

Description

The Notholithocarpus (prev. Lithocarpus) densiflorus leaves are alternate, 7–15 cm (2.8–5.9 in), with toothed margins and a hard, leathery texture, and persist for three to four years. At first 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 persisting longer but eventually wearing off too.