Aphananthe aspera Seeds | Muku Tree

Rough toothed leaves and dark fruit of Muku Tree (Aphananthe aspera) — Muku Tree (*Aphananthe aspera*): Cannabaceae, a streamside tree of China, Japan, Korea and Taiwan.

LATIN NAME: Aphananthe aspera

COMMON NAME: Muku Tree

Plant Profile

Muku tree is a deciduous tree of the hemp family, native to China, Japan, Korea and Taiwan, where it grows along streams and forest edges to twenty metres. Its leaves are oval, sharply toothed and remarkably rough, and its small green flowers appear in spring.

The fruit is a black drupe that birds take in autumn, and the trunk is grey and smooth, with old trees often leaning out over water. The crown is broad and the shade deep, which is why the tree is valued in parks and temple grounds. The bark is used in Japan for a dark dye, and the timber for the handles of tools.

Science & Biotechnology

The roughness of the leaves comes from silica bodies in the epidermis, and they were used in Japan as a fine abrasive for polishing wood, lacquer and metal, a use recorded for centuries. The species is also studied in riparian ecology, since its roots stabilise stream banks and its fruit feeds the birds that disperse the seed.

Its timber anatomy has been described in detail because the wood is unusually hard for a tree of this size, and its bark fibres have been examined for papermaking. Genetic work has looked at how populations on either side of the East China Sea differ.

Uses & Benefits

The wood is hard, heavy and difficult to work, and it is used for furniture, tool handles and printing blocks. The bark yields a strong fibre that was made into rope and paper, and the leaves were the traditional abrasive of Japanese craftsmen.

In the garden it is grown as a shade tree in parks and large gardens, and it is valued for the way its canopy shelters a stream. It is uncommon in Western cultivation, which makes it a tree for collectors of East Asian woody plants. The wood is also used for the soles of geta, the wooden sandals.

The leaves were also used to polish the lacquer on sword scabbards, and the tree was planted near workshops for that reason. Its fruit is eaten by birds but is not used by people, and the wood is avoided by carvers because it blunts tools quickly.

Growing from Seed

Sow fresh seed in autumn, one centimetre deep, and keep it cool and moist; germination is usually in spring. Seedlings are slow and should be grown in deep pots for two years.

Plant out in sun or light shade in moist, deep soil, and water in dry spells. The tree tolerates pruning but is best left to develop its natural shape, and it should have room for its roots to reach water. The seed should be sown within days of collection, since it loses viability when dried, and the pots kept in a cold frame through winter.

Our Take

An uncommon tree with an unusual history: sandpaper leaves, hard timber and a graceful habit over water. It suits a large garden or a park rather than a small plot.

Tree Seeds