Characteristics of Kaya Tree “榧” (Torreya nucifera) in the Wild

Torreya nucifera
Kaya “榧” or Japanese Torreya (Torreya nucifera) is a slow-growing, long-lived conifer tree. This tree is native to Japan (tohoku, yakushima, gunma, dan fukushima) and Jeju Island in South Korea.

The kaya tree is valued for its wood for the construction of Go boards and Shogi boards for its beautiful yellow-gold color, smooth and uniform ring texture, and the click sonic quality of the stone on its surface.

Today the kaya tree is protected in Japan due to its rarity. The IUCN Redlist has also categorized Torreya nucifera as Least Concern (LC) since 2010.

The thick Go boards are harvested from ancient kaya trees which makes them very expensive. The price of one thick Go board can touch $19,000.

Shin-kaya or Kayabaru in Japanese, today is made from the wood of Alaskan, Tibetan, or Siberian white spruce. Go boards or Shogi boards made not of real kaya wood are much cheaper.


In Japanese esoteric Buddhism such as Shingon, the leaves of the tree, as well as the oil extracted from the kaya tree, have certain uses in rituals. The leaves of the kaya tree (representing the flower and oil) are burned as lamps during the long meditation practice known as Morning Star meditation.

In addition, the kaya trees have cultural and historical significance for the people who live around them, such as the Japanese Torreya samin-ri.

An old kaya tree grows near the Nishinomaru-enokida Gate in Nagoya Castle. The height is about 16 meters and the diameter of the lowest trunk is 8.7 meters. Its age is estimated to be more than 900 years. The tree was already there when the castle was built. It is the only government-designated natural monument in Nagoya. The tree regained its viability despite the damage from an air raid in 1945.


Characteristics of Kaya Leaf

Torreya nucifera Leaf

The leaves are evergreen, needle-like, 2-3 cm long, 3 mm wide, with sharply twisted tips and two whitish stomatal bands on the underside. They are spirally arranged but twisted at the base to lie horizontally on either side of the stem.


Characteristics of Kaya Fruit

Torreya nucifera Fruit

Kaya trees produce mostly male or mostly female cones, but usually, several cones of the other sex are present.

The male cones are 5-6 mm in diameter, in double rows along the bottom. Female cones appear in groups of 3-8, maturing in 18-20 months.

The seed is single, surrounded by a fleshy layer, 2 cm long and 1.5 cm wide.


Characteristics of Kaya Tree

Torreya nucifera Tree

Kaya trees can grow up to 20-25 meters with a trunk diameter of up to 3 meters. This tree is resistant to extreme weather and can grow in forests where the sun is not so bright.

The wood is light yellow in color, shiny, dense, and gives off an insect repellent scent. The material is a little heavy, elastic, durable, and relatively easy to process. There are many shades that kaya wood gives off as it ages.


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