Castanopsis cuspidata ("Tsuburajii")

Japanese name: ツブラジイ （円椎）
Scientific name: Castanopsis cuspidata

[Overview]
An evergreen tree reaching 20 m in height and 1 m in diameter.
The bark has no fissures, or only shallow, sparse ones.
The branches divide well and form a large, rounded crown.
Young branches are sparsely hairy.
The leaves are simple and alternate, elliptic-ovate to lanceolate, 5–10 cm long.
The leaf margins are entire or have a few wavy teeth.
The upper surface of the leaf is dark green, and the underside is silvery brown.
There are male flowers and female flowers.
The male flowers are borne in large numbers on erect spikes 8–10 cm long, arising from the scale leaves at the base of new branches and from the leaf axils; they are pale yellow and give off a distinctive smell that attracts many insects.
The female inflorescences stand erect in the leaf axils of new branches and are about 8 cm long.
The fruit is an ovoid-globose to globose nut (a so-called acorn), 6–13 mm long, enclosed in a cupule (involucre) with scale-like projections.
The fruit ripens in autumn of the following year.

[Uses]
The wood is used as firewood and charcoal material and as bed logs for growing shiitake mushrooms.
The fruit has no bitterness and can be eaten as it is.

[Cultivation]
Propagate from seed.
The germination rate drops drastically if the seeds are dried, so sow them immediately after collecting or store them so that they do not dry out.
It is not suited to planting in cold regions.
It grows in sun to partial shade and prefers slightly moist, well-drained soil.
Cultivation is easy.
Fertilizer is not particularly necessary, but giving oil cake as fertilizer in winter improves growth.
Pests and diseases include powdery mildew and the larvae of longhorn beetles (teppo-mushi).

[Notes]
It closely resembles Sudajii, and the two are distinguished by the way the bark splits, the size of the leaves, and the shape and size of the fruit, but there are intermediate forms and it is difficult.

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