|Leaves and pollen catkins. Osaka, Japan.|
|Subgenus:||Quercus subg. Quercus|
|Section:||Quercus sect. Quercus|
It is a deciduous tree growing to 30 metres (98 ft) tall with a trunk up to 1 m (3 ft) in diameter with fissured gray-brown bark. The leaves are obovate to oblong, glabrous above, glabrous to densely grey-white hairy below, mostly 10–20 centimetres (4–8 inches) long and 5–14 cm (2–5+1⁄2 in) wide (rarely up to 30 cm (12 in) long and 16 cm (6 in) wide), with 9 to 15 lobes on each side, and a 10–13 mm (3⁄8–1⁄2 in) petiole.
The flowers monecious catkins. The acorns are 17–25 mm (5⁄8–1 in) long and 13–18 mm (1⁄2–3⁄4 in) wide, a third to a half enclosed in a green-grey cup on a short peduncle; they are solitary or 2–3 together, and mature in about six months from pollination. A long-lived tree, it is slow-growing.
- Quercus aliena var. aliena. Leaf margin wavy; leaf greyish below.
- Quercus aliena var. acutiserrata Maxim. Leaf margin serrated, with sharp serration; leaf densely hairy below with greyish hairs.
- Quercus aliena var. pekingensis Schottky. Leaf margin serrated, with rounded serration; leaf glabrous or only slightly hairy below.
- Quercus aliena var. alticupulifirmis H.Wei Jen & L.M.Wang (not accepted by Flora of China).
- Quercus aliena var. pellucida Blume (not accepted by Flora of China).
It is native to East Asian states of Korea, Japan (where it occurs in Honshu, Shikoku, and Kyushu), mainland China (where it occurs in the provinces of Anhui, Gansu, Guangdong, Guangxi, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Liaoning, Shaanxi, Shandong, Shanxi, Sichuan, Yunnan, and Zhejiang) and Taiwan.
Cultivation and uses
The wood is used in East Asia for boat building and wood flooring for houses. The seeds can be crushed into a powder and used as a soup thickener and for mixing into cereals and breads. The seeds when roasted can also be used as a substitute for coffee. Galls produced by the larvae of insects are a rich source of tannin.
Quercus aliena was introduced to Europe in 1908, but remains rare in cultivation outside of its native area. The taproot is deep, making older plants difficult to move. It grows in full sun or partial shade and tolerates strong winds. It can grow in almost any type of soil as long as not waterlogged.
- Species was originally described and published in Mus. Bot. 1(19): 298. 1851. "Quercus aliena Blume". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens. Retrieved July 19, 2010.
- Lee, Sangtae; Chang, Kae Sun, eds. (2015). English Names for Korean Native Plants (PDF). Pocheon: Korea National Arboretum. p. 599. ISBN 978-89-97450-98-5. Retrieved 12 March 2019 – via Korea Forest Service.
- "Quercus aliena". International Oak Society oak checklist.
- "Quercus aliena". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved January 19, 2018.
- "Quercus aliena". Flora of China – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Su, Mong-Huai; Wu, Sheng-Chieh; Hsieh, Chang-Fu; Chen, Sin-I; Yang, Kuoh-Cheng (2003). "Rediscovery of Quercus aliena Blume (Fagaceae) in Taiwan" (PDF). Taiwania. 48 (2): 112–117.
- "Quercus aliena". Plants for a Future.
- Bean, W. J. (1976). Trees and shrubs hardy in the British Isles. Vol. 3 (8th revised ed.). John Murray. p. 461.