It is a monoecious evergreen tree growing to 25 m tall, with a trunk diameter of up to 1 m. The shoots are orange-brown, with scattered pubescence.

The leaves are needle-like, 8–16 mm long, rhombic in cross-section, dark bluish-green with conspicuous stomatal lines.

The main cause of decline is the loss of natural regeneration after typhoons, with windblown trees being replaced by the planting of other faster-growing commercially valuable species.

There is little genetic exchange between different fragmentary locations where it grows, and the total area of occupation by this tree is less than 100 square kilometres (39 sq mi).

The name was first published as "koyamai", but this is an orthographical error to be corrected under the provisions of ICBN Article 60.