Castanopsis delavayi

Castanopsis delavayi is an evergreen tree in the beech family, Fagaceae. Its native range spans southern China to northern Myanmar. It grows in a subtropical climate within that range. Chinese records include Guangdong, Guizhou, Sichuan and Yunnan. It inhabits mixed forests and forests of evergreen broad-leaved trees. These sites lie at elevations of 4,921–9,186 feet [1,500–2,800 metres].

The tree reaches about 49 feet [15 metres] in height. It keeps its leaves throughout the year. Its size suits the canopy layer of a woodland garden. Flowers appear from April to May, in catkins. Each tree bears both male and female flowers. The individual flowers are either male or female. Wind and midges help pollinate them. The catkins give off an unpleasant scent that draws midges. This scent resembles that of hawthorn flowers.

Seeds ripen from October to November. They need two growing seasons to mature after fertilization. Each seed can measure about 0.55 inches across. Plants For A Future lists the seeds as edible. However, it gives no firm details on their preparation. It rates their food value at two out of five. The same source reports no known hazards or medicinal uses. That lack of reported hazards does not establish safety for pets.

For cultivation, choose a sheltered site with partial shade. This tree prefers moist soil and a deep loam. It can also grow in heavy clay soil. Mildly acid to neutral soil suits it, but avoid lime. Plants For A Future lists USDA hardiness zones 7–10. It reports cold tolerance in Britain's milder areas. Yet warmth matters as well as winter survival. The tree fares better in a warm continental climate. Britain's maritime climate does not suit it well.

Propagation uses seed, which needs a period of cold treatment. Sow fresh seed in a cold frame when ripe. Seed loses viability soon, so do not let it dry. Cool, moist storage can preserve it for a few months. Soak stored seed for 24–48 hours in warm water before sowing. Germination can take one to three months at 59°F. Move seedlings into separate pots once large enough to handle. Young plants may need a cold frame through their first winter.