Castanopsis tribuloides

Castanopsis tribuloides is an evergreen tree in the beech family. Its native range runs from the Himalayas to Indo-China. It also grows in southern China and Bangladesh. It lives in subtropical regions and hill forests. In India, it reaches heights of about 5,900 feet [1,800 metres] above sea level. In western China, it grows in forests with broad-leaved evergreen trees.

Size reports differ between sources. Plants For A Future lists a height of 26 feet [8 metres]. Useful Tropical Plants describes trees reaching 39–59 feet [12–18 metres]. These larger figures come from forest and timber accounts. The trunk can grow about 2 feet [0.6 metres] thick. It can remain branch-free for 39 feet [12 metres]. The trunk is fairly straight and round. The tree keeps its leaves year-round and grows fast.

Flowers appear from May to June, according to Plants For A Future. One tree bears both male and female flowers. Wind and midges carry the pollen. Seeds ripen from October to November. Each seed measures about 0.6 inches [16 millimetres] across. The seed cases bear strong, sharp spines. Fallen cases can hurt animals' feet. People eat the seeds raw or cooked. Their size and taste resemble hazelnuts. In Vietnam, growers raise the tree for its edible seeds. Roasting is one way to prepare them.

Plants For A Future lists moist loam or clay as suitable soil. It also lists mildly acid to neutral soil and partial shade. Its notes on British hardiness are uncertain and conflict. They do not establish a firm hardiness limit. Fresh seed needs cold treatment and must not dry out. Cool, moist storage can keep it viable for a few months. Germination takes one to three months at about 59°F [15°C]. Plants For A Future lists the tree for woodland canopy planting.

The tree grows back well after cutting to the base. In India, people use this trait to produce fuel and small timber. Its wood is fairly hard but lacks durability. Uses include boards and roof shingles. In Thailand, it serves in projects that restore forest cover. Plants For A Future records no medicinal use or known toxic hazard. The sharp seed cases remain a clear physical risk.