Lithocarpus pachyphyllus Seeds | Thick-leaf Tanoak
LATIN NAME: Lithocarpus pachyphyllus
COMMON NAME: Thick-leaf Tanoak
Plant Profile
Thick-leaf tanoak is an evergreen tree of the warm hills, fifteen to twenty-five metres tall, with leathery, dark-green leaves that are pale and felted beneath and small acorns set in a shallow cup. The crown is dense and rounded, the bark is grey and rough, and the tree keeps its foliage through the year, which is why it is valued as cover and as a screen. It is a species of the eastern Himalaya and south-western China, growing in mixed forest at moderate altitude. The new leaves are flushed pink and soft, and they harden within a few weeks into the thick, stiff blades that give the species its name.
Science & Biotechnology
Lithocarpus is the stone oak genus, with several hundred species in Asia, and its classification has been reshaped by molecular work that places it firmly in Fagaceae but separate from Quercus. The thick, leathery leaves of this species are an adaptation to altitude and to dry seasons, with a dense indumentum beneath that reduces water loss. Its acorns are dispersed by rodents and by gravity, and the species is a minor timber tree in its range. Its seed biology is typical of the genus: recalcitrant, short-lived and intolerant of drying. The genus is also unusual in having both erect and spreading catkins, a character used to split it into sections. Its timber is also used for charcoal in parts of Yunnan, where the wood burns hot and slow.
Uses & Benefits
The wood is hard, close-grained and used locally for tools, fuel and small construction, and the acorns are edible after leaching, as with other tanoaks. In the garden it is a solid evergreen shade tree for a mild, moist climate, useful as a screen or a background tree, and it is one of the more cold-tolerant of the Asian stone oaks. It is not a quick tree, and it is best planted where it can stay. Its dense crown also makes it a good windbreak, and it is one of the few broadleaved evergreens that will hold a slope in heavy rain. The fallen leaves are tough and slow to break down, so they make a poor mulch but a good path surface.
Growing from Seed
Sow the acorns as soon as they are ripe, since they are recalcitrant and die if they dry. Two centimetres deep in a deep pot, kept moist and cool, and germination follows in spring. The radicle emerges first and resents disturbance, so plant young. Grow the seedling in light shade for a year, then in full sun, in deep, moist, acid soil. Mulch to keep the roots cool, and water through the first two summers. It is slow for the first three years and then steady, and it should never be allowed to dry out completely.
Our Take
A quiet evergreen oak of the Asian hills, slow, solid and useful where a screen is wanted. Plant it young, keep it mulched, and it will do the rest for decades.
Related Reading
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