Araucaria heterophylla (Norfolk Island pine, "Kobanonan'yosugi")

Japanese name: コバノナンヨウスギ （小葉南洋杉）
Scientific name: Araucaria heterophylla

[Overview]
An evergreen coniferous tree that can exceed 60 m in height and 1.8 m in diameter.
The bark is grayish brown and peels off in fine scales.
The trunk grows straight and vertical, and thick branches are usually arranged regularly in whorls of 5 (4–7), extending horizontally or slightly obliquely to form layers, giving a beautifully balanced, symmetrical conical tree shape.
The twigs are densely arranged alternately in two rows, extending horizontally or hanging down slightly.
The leaves are arranged alternately in a spiral, and their shape differs between young and mature trees.
The leaves of young trees are needle-shaped, 1–1.5 cm long, with sharply pointed tips.
The leaves of old trees are lanceolate to ovate-triangular, 0.5–1 cm long, scale-like, densely overlapping and curving upward.
The plant is usually dioecious, but may be monoecious.
Both male and female inflorescences are borne at the branch tips; the male inflorescence is cylindrical and the female inflorescence is nearly spherical.
The cones are 10–12 cm long and 12–14 cm in diameter, ripen over about 18 months, and contain a great many seeds.
The cones are 10–13 cm in diameter and contain a great many seeds.
The seeds are about 2.5–3 cm long and 1 cm in diameter, with broad wings.

[History]
It arrived in Japan at the end of the Meiji period.

[Uses]
This group is counted as one of the world's three great park trees.
The seeds are edible.
The timber is useful.

[Cultivation]
Propagate from seed or by cuttings.
When growing from seed, it is best to sow immediately after collecting, but seed that is refrigerated can still germinate the following year.
The optimum temperature for germination is around 25°C.
For cuttings, use only the tip of the main trunk.
If side branches are used, they grow only sideways and do not develop the natural tree shape.
It can overwinter outdoors in regions without frost.
It prefers a sunny place with well-drained soil.
For potted plants, water thoroughly from spring to autumn when the soil surface dries, and keep it on the dry side in winter.
For plants in the ground, rainfall is sufficient.
Apply slow-release fertilizer placed on the soil in spring and autumn.
Pests include spider mites and scale insects.

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