Castanopsis acuminatissima aka Papua New Guinea Oak

Castanopsis acuminatissima is an evergreen tree in the Fagaceae family. Its common names include Castanopsis chestnut and white oak. Its native range runs from Bangladesh to southern China and Papuasia. It also grows across much of Southeast Asia. It lives in wet tropical regions, often on hillsides and ridges. It forms part of the upper canopy in old forests. Recorded sites lie at 984–8,202 feet [300–2,500 metres] above sea level.

This fast-growing tree forms a broad, spreading crown. Garden references give a height and spread of 82 feet [25 metres]. Broader accounts report heights of 33–118 feet [10–36 metres]. The straight trunk can reach 1–3 feet [0.3–0.9 metres] across. Buttresses may rise to 6.6 feet [2 metres]. They can extend 4.9 feet [1.5 metres] from the trunk. Roots grow near the surface. Suckers often form a ring around the trunk's base. The tree keeps its leaves throughout the year.

Wind carries pollen between the flowers. Spiny cases hold the edible seeds. Each seed can measure about 0.6 by 0.4 inches. People eat them raw, though cooking is more usual. They boil or roast them for food. Cooked seeds have a taste compared with rice. In parts of New Guinea, seeds provide an important local food. People plant trees near settlements and tend wild trees too. Eating many raw nuts has caused mouth ulcers and anaemia. Plants For A Future lists no known medicinal uses.

For cultivation, provide full sun and moist soil with good drainage. The tree accepts sandy, loamy, and clay soils. It tolerates mildly acid, neutral, and mildly alkaline conditions. Plants For A Future lists USDA zones 10–12. Fresh seed germinates well when sown soon after collection. Growers can move seedlings that sprout on their own. Basal suckers often fail to establish after transplanting.

Northern Thailand uses this tree in mixed woodland restoration plantings. Its fast growth helps rebuild tree cover on damaged sites. Fallen leaves build a thick mulch that limits other plants. This matters when choosing plants to grow beneath its crown. The pale wood supplies both local and commercial needs. Uses include furniture, floors, bridges, plywood, and boats. Builders also use trunks and bark in traditional houses.