Quercus poilanei Hickel & A. Camus

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Credits

Allen Coombes & Roderick Cameron (2022)

Recommended citation
Coombes, A. & Cameron, R. (2022), 'Quercus poilanei' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/quercus/quercus-poilanei/). Accessed 2024-04-19.

Genus

Quercus
Subgen. Cerris, Sect. Cyclobalanopsis

Common Names

黄背青冈 (huang bei qing gang)
Sồi bộp
Sồi áo tơi

Synonyms

Cyclobalanopsis poilanei (Hickel & A. Camus) Hjelmq.
Quercus flavescens Hickel & A. Camus

Other taxa in genus

Glossary

herbarium: A collection of preserved plant specimens; also the building in which such specimens are housed.
type specimen: A herbarium specimen cited in a taxonomic account to define a particular species or other taxon.

References

Credits

Allen Coombes & Roderick Cameron (2022)

The leaves of Quercus poilanei are conspicuously veined with an attractive tomentum on the underside. Seen here on Daming Shan, Guangxi, China in October 2012. Image Tom Hudson.

Tree to 16 m or more tall and 60 cm diameter, sometimes shrubby at high altitudes, bark grey, wrinkled. Young shoots with a dense, golden, velvety tomentum becoming grey and more or less glabrous. Leaves evergreen, leathery, elliptic-oblong to obovate, to 10 × 6 cm, smaller on slow-growing shoots of mature trees, tapered or rounded at the base, shortly acuminate at the apex, margin entire, sometimes undulate to shallowly toothed towards the apex, lateral veins up to 14 on each side of the midrib, impressed above, conspicuously raised beneath. Leaves are tomentose on both sides when they emerge becoming glossy dark green above with a dense yellowish tomentum beneath. Petiole to 1.5 cm. Infructescence to 7 cm with up to 10 short-stalked cupules. Cupules saucer-shaped, to 0.6 × 1.5 cm, with 7–8 rings of densely tomentose scales, at least the upper ones crenate. Acorns ovoid to nearly spherical, to 2 × 1.5 cm, only the base enclosed in the cup and ripening the following year. (Huang et al. 1999; Menitsky 2005; le Hardÿ de Beaulieu & Lamant 2010; Hickel & Camus 1921).

Distribution China Guangxi Thailand North Vietnam

Habitat Subtropical evergreen or deciduous humid forests with other oaks, Lithocarpus, Ericaceae and bamboos, often on mountain summits or ridges at 1200–1800 m asl.

USDA Hardiness Zone 8

RHS Hardiness Rating H4

Conservation status Least concern (LC)

Quercus poilanei was introduced by Tom Hudson in 2012 from 1700 m at the summit of Daming Shan, Guangxi, China. Rare in cultivation, there are four small plants about 1 m tall at Tregrehan (T. Hudson pers. comm. 2021). A plant of the same origin and size is at Chevithorne Barton, UK, which James MacEwen (pers. comm. 2021) describes as astonishingly beautiful.

Specimens in the Paris Herbarium record other information about this species. In 1920 Poilane collected it from Ba-Na, Vietnam where it grew in a large quantity and noted that the tree was 20 m tall and unbranched for 10 m. On a specimen collected at the summit of Nui Bach Ma Station in 1938 he noted that the hard wood is used for ‘colonne’, presumably as a building material. J.F. Maxwell collected it in Thailand and noted that the nuts are chewed with betel and the crushed seeds are used to treat burns (Muséum national d’histoire naturelle 2022).

It was named for Eugène Poilane, French botanist for the Forest Service of Indochina, who collected the type specimen at Ba-Na, Annam (Vietnam) in 1920. The local name in China can be translated as ‘yellow-backed evergreen oak’.

The veins on the leaves of Quercus poilanei (up to 14 on each side of the midrib) are impressed above; Vietnam, September 2018. Image Son Hoang.

Quercus poilanei leaves with slightly paler undersides on a plant at Tregrehan, Cornwall, UK. October 2020. Image Tom Hudson.

Foliage of Quercus poilanei from Guangxi, on a young plant at Tregrehan Garden, UK (20 September 2022). Image © Jan De Langhe - Arboretum Wespelaar.

Lamina lower surface with partially detached indumentum (Tregrehan Garden, UK – 20 September 2022). Image © Jan De Langhe - Arboretum Wespelaar.

Quercus poilanei young leaves on a small plant at Iturraran Botanical Garden, NE Spain, retain some of the tomentum on the upper surface, which will soon become glossy dark green; August 2018. Image Francisco Garin.

Quercus poilanei new leaves at the Iturraran Botanical Garden, coated in tomentum, June 2019. Image Francisco Garin.

The dense yellow tomentum that coats the leaf undersides of Quercus poilanei leaves; Vietnam, September 2018. Image Son Hoang.

New Quercus poilanei leaves are tomentose on both sides when they emerge; Vietnam, September 2008. Image Son Hoang.

Quercus poilanei; a ripening acorn in its saucer-shaped cupule; Vietnam, September 2018. Image Son Hoang.

Quercus poilanei acorns ripen in the second year and are born on the infructescence in groups of up to 10 on short-stalked cupules; Vietnam, September 2018. Image son Hoang.

Quercus poilanei acorn cups have tomentose rings with crenate margins. Daming Shan, Guangxi, China, October 2012. Image Tom Hudson.

Quercus poilanei CDHM 14693 catching the light (Rhododendron Species Botanical Garden, Seattle, June 2023). Image John Grimshaw.

Maturing new growth of Quercus poilanei CDHM 14693 (Rhododendron Species Botanical Garden, Seattle, June 2023). Image John Grimshaw.