Quercus longinux Hayata

Endemic to the broadleaved evergreeen forests of Taiwan, this species is recognized by most authorities, despite Menitsky’s view that it should be considered a subspecies of Q. glauca. Mark Weathington (2014) observed that in habitat the smooth grey-barked trunk is branchless up to two thirds of the total height, though in cultivation is tends to form an upright oval to round-headed tree about 10 m tall.

This species has been introduced several times but has never performed very well in cultivation in Europe. A plant at Tregrehan, UK, grown from seed received from the Taiwan Forestry Research Institute reached several metres tall before dying suddenly (T. Hudson pers. comm. 2020). This plant had narrow, entire, willow-like leaves. A plant at Sir Harold Hillier Gardens grown from seed collected by Allen Coombes in Taiwan in 2003 (CMBS 655) was 2.5 m × 1 cm in 2020 (The Tree Register 2021). At Arboretum des Pouyouleix, France, plants of the typical form and var. kuoi raised from seed collected by Béatrice Chassé in Taiwan grew very slowly and have mostly died (B. Chassé pers. comm. 2022).

It is rare in the USA, but a plant growing at J.C. Raulston Arboretum, North Carolina, perhaps gives an indication of the preferred climate for this species. Weathington (2014) wrote that: ‘The JCRA plant was received from the Taiwan Forestry Research Institute index seminum in 2001 and is now over 6 m tall growing in sun and rich soil […] The 2014 winter temperatures of –13 °C caused significant tip dieback so this plant will likely be relegated to zone 8 gardens.’

The epithet means ‘long nut’. Hayata (1911) compared it to Q. myrsinifolia, stating that it differed in its much longer acorn. It can also be distnguished from this species by the number of rings in the cupule (more than six in Q. longinux) (le Hardÿ de Beaulieu & Lamant 2010). The common name in Chinese can translated as ‘long-fruited evergreen oak’.