Castanopsis javanica

Castanopsis javanica is an evergreen tree in the Fagaceae family. Common names include spiny oak and Java chinkapin tree. Its native range runs from southern Myanmar to western Malesia. Records include Malaysia, Sumatra, Kalimantan, and western Java. It grows in the wet tropics, in old-growth and some secondary forests. It occurs up to about 5,400 feet [1,650 metres]. Some records reach 6,560 feet [2,000 metres].

Garden references give a height and spread of 82 feet [25 metres]. Broader forest records give heights of 33–131 feet [10–40 metres]. The trunk can have grooves along its length. Its diameter ranges from about 0.7–3.3 feet [0.2–1 metre]. The tree keeps its leaves year-round and grows at a moderate rate. The supplied sources give no clear leaf shape or bark colour. Its large size sets it apart from small garden trees.

Insects pollinate the flowers, but the sources give no bloom season. Each spiny case holds one seed with a thin shell. Seeds have a flat, disc-like or low, egg-shaped form. They measure 10–15 millimetres long and 20–25 millimetres wide. The seeds are edible, and growers in Java raise trees for nuts. Seed is also the listed means of propagation. The sources give no details on preparing the nuts for food.

This tree prefers moist soil and can grow in sun or light shade. Listed soil types include sand, loam, and clay. The stated pH range runs from mildly acid to mildly alkaline. PFAF lists USDA zones 10–12, which suits its tropical range. Its separate UK zone number does not establish an RHS hardiness rating. The tropical plant reference says trees respond poorly to coppicing. Neither source gives specific pest or disease problems. PFAF does not flag the tree as weedy.

Its uses extend beyond its edible seeds. Local builders use the heavy, durable wood for house posts and other building work. Other uses include furniture, poles, and door and window frames. Wild timber enters trade under the name Berangan. People also use the bark to make rice storage vessels. Bark tannins provide dye and help protect fibres from weather. The sources report no known medicinal uses or hazards. That lack of reported hazards does not establish safety for pets. The documented value centres on food, timber, and bark products.