Kindly sponsored by
The Trees and Shrubs Online Oak Consortium
Allen Coombes & Roderick Cameron (2021)
Coombes, A. & Cameron, R. (2021), 'Quercus guyavifolia' from the website Trees and Shrubs Online (treesandshrubsonline.
Tree to 15 m tall but in the wild often cut back for fuel and a low shrub. Bark dark grey, with longitudinal ridges. Young shoots with a dense, golden, red or brownish tomentum becoming glabrous with pale lenticels. Leaves evergreen, rigid and leathery, glossy dark green above with up to 12 veins on each side of the midrib, to 9 × 5 cm, rounded to slightly cordate at the base, obtuse to rounded at the apex and edged with spiny teeth or entire, often wavy-edged. Pubescent above when young, becoming glabrous or nearly so, densely and persistently golden brown tomentose beneath, the tomentum grey when the leaves are young. Petiole brown-tomentose, to 8 mm long. Infructescence with a stout peduncle to 6 cm long, cupules solitary or in pairs. Cup to 1.2 × 2 cm, with a splayed undulate margin and grey-brown tomentose scales with a reddish apex. Acorns ovoid to nearly globose, to 2.4 × 1.4 cm, tomentose at the apex and about half enclosed in the cup, ripening the second year. (Coombes & Rix 2012).
Distribution China Guizhou, Sichuan, Yunnan
Habitat Mountainsides often on limestone at 2000–4000 m.
USDA Hardiness Zone 7
Conservation status Least concern (LC)
Introduced by Keith Rushforth (KR 2823) in 1993 from a 15 m tree in the Zhongdian Gorge, Yunnan. A tree planted in his collection in Devon was about 4.5 m tall in 2012 and is probably the largest in cultivation. This tree has produced acorns, and seedlings from it are at Tregrehan.
Seed was later sent from Yunnan to the Sir Harold Hillier Gardens, UK, in 2003; one plant there was 2.3 m in 2020 (B. Clarke pers. comm.). Plants from the same collection are 2 m tall and across at Thenford, Northamptonshire (D. Webster pers. comm. 2020), 3–4 m at Tregrehan, Cornwall (T. Hudson pers. comm. 2020) and more than 7 m × 7.5 cm at Chevithorne Barton, Devon (J. MacEwen pers. comm. 2020). There are also plants at Arboretum Robert Lenoir, Belgium and Arboretum des Pouyouleix, France from Tom Hudson. Two plants in the latter garden were 3 m tall in 2020 (B. Chassé pers. comm.). According to Eike Jablonski (pers. comm. 2020) this species grows well on alkaline soil over limestone at Ettelbruck, Luxembourg where it flowers freely but does not set acorns. Two plants grown from seed collected at about 3410 m on Luoji Shan, Sichuan in 1990 (H&M 1471) are at Sonoma Botanical Garden, USA (Quarryhill Botanical Garden 2001) and one plant of the same collection is at the Howick Arboretum in Northumberand, UK (and was initially identified as Q. monimotricha). The parent plant was a shrub to 2.5 m with spiny leaves to 4.5 × 3.5 cm, mustard-yellow beneath.
Although this species is rare in cultivation it is one of the most attractive of the golden oaks in the colour of the underside of its leaves.
The specific epithet has been spelt in different ways, but the original spelling is retained here as it is based on what was regarded as a common name for the guava (guyava) and not on the genus Guajava (= Psidium).