Castanopsis cuspidata

Castanopsis cuspidata (Japanese chinquapin; Japanese tsuburajii, 円椎) is a species of Castanopsis native to southern Japan and southern Korea.

It is a medium-sized evergreen tree growing to 20–30 m tall, related to beech and oak. The leaves are 5–9 cm long and 2–4 cm broad, leathery in texture, with an entire or irregularly toothed margin. It grows in woods and ravines, especially near the sea.

The cotyledon of the nut is eaten boiled or roasted.

Its dead wood serves as host to many mushroom types, most notably the shiitake, whose Japanese name (椎茸) is composed of shii (椎), and take (茸).