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Allen Coombes & Roderick Cameron (2021)
Coombes, A. & Cameron, R. (2021), 'Quercus libani' from the website Trees and Shrubs Online (treesandshrubsonline.
Tree, sometimes shrub, 6–15 m tall, trunk up to 60 cm diameter, foliage deciduous, sometimes semi-evergreen depending on climate, canopy broad. Bark grey and smooth at first, then deeply fissured and darker. Young shoots slender, angular, at first clothed with minute down but soon glabrous, pale brown to dark red, with small lenticels; buds around 3–4 mm, ovoid, apex slightly acute, yellowish brown, ciliate, terminal buds bearing stipules. Leaves distributed over shoots, oblong to oblong-lanceolate, base rounded to subcordate, frequently asymmetrically, 5–15 cm × 1–6 cm wide, margin with 8–14 pairs of regular or irregular, triangular teeth, 1–1.5 cm long, ending in a 2–4 mm aristate mucro (extension of the secondary vein beyond the blade margin), sinus rounded; leaves frequently emerge covered in stellate pubescence, especially in vein axils and on the undersurface; soon becomes glossy green above, pale green or yellowish green and glabrous below, or slightly pubescent, especially on the midrib and veins; 9–18 pairs of secondary veins prominent beneath, intercalary veins absent. Petiole glabrous or slightly pubescent, 0.8–2 cm long. Cupule hemispherical to bell-shaped or cup-shaped, 1.5–3.2 cm tall × 2–3.5 cm wide, pubescent; scales broadly rhomboid, all appressed, or medium scales recurved, or uppermost elongated and spreading, forming a fringe; cup encloses two thirds to half of the nut; acorn cylindrical or ellipsoidal, light brown to almost black, 2–3.5 cm long × 2.2–3 cm wide, base truncated, apex rounded, slightly mucronate, with whitish or yellowish light pubescence, borne singly or in pairs, almost sessile or on a thick woody stalk not longer than 1.5 cm, ripening in the second year. (le Hardÿ de Beaulieu & Lamant 2010; Avishai 2017; Hedge & Yaltirik 1994).
Distribution Iran West Iraq Northwest Syria North & West Turkey East Anatolia
Habitat Forming pure populations or mixed with other oaks such as Q. infectoria, Q. brantii or Q. cerris, the latter only on its western limits. It thrives between 700 and 2,000 m of elevation.
USDA Hardiness Zone 7
RHS Hardiness Rating H6
Conservation status Least concern (LC)
Despite its epithet and common names, Lebanon Oak is not native to Lebanon (or is extremely rare there, see below): it is found in the mountains of Asia Minor and stretches from the Turkish-Syrian border towards eastern and southeastern Anatolia, then into Kurdistan in Iraq, and further to the Zagros mountains in Iran. In the Taurus Mountains of Turkey it forms vast forests. It prefers clay-limestone and loamy soils on sunny slopes and appears indifferent to soil pH. Its hard, heavy wood is used in construction in Turkey and in Kurdistan its acorns are consumed roasted or ground to make acorn flour (le Hardÿ de Beaulieu & Lamant 2010).
It was introduced to Paris in 1855, from seed sent by Benedict Balansa. The species is very variable, particularly in the amount of pubescence on the twigs and leaves, the size of the acorn cup, and the shape and size of the cupule scales. Leaves with irregular deep lobes are sometimes found on young branches. This variation contributed to the numerous synonyms which may have originally been applied to extreme forms of the species; Q. regia, for example, was the name given to an unusually broad-leaved variant (Elwes & Henry 1906–1913, Hedge & Yaltirik 1994).
It is found in several gardens in Britain, where specimens have grown taller than the 15 m reported for trees in native habitat. The champion grows in the gardens of Tortworth Court Hotel, Gloucestershire, and at 27 m × 1 m dbh it is head and shoulders above the runner up in Roath Park, Glamorgan, Wales (22 m × 79 cm) (Tree Register 2021). A notable specimen stands in the garden of the Botanical Garden of Lisbon, Portugal, a modest 17.8 m tall in 2015 but with an estimated dbh of 1.3 m; it is thought to have been planted around 1890 (monumentaltrees.com 2021). Of trees growing at the Jerusalem Botanical Gardens, three are of Turkish origin (The Jerusalem Botanical Gardens 2021).
Quercus libani hybridizes with Q. brantii in northern Iraq (le Hardÿ de Beaulieu & Lamant 2010); it also forms an intersectional hybrid with Q. infectoria subsp. veneris q.v. (Menitsky 2005). The best known hybrid in cultivation, however, is with Q. cerris, known as Q. × libanerris, q.v., first described as a cultivated plant but also found in the wild. Quercus libani offered in nurseries often turns out to be crossed with Q. cerris (le Hardÿ de Beaulieu & Lamant 2010).
It was described by Guillaume Olivier in 1804, in his account of a journey through the Ottoman Empire, Egypt, and Persia. Elwes and Henry (1906–1913) claimed that Olivier found the oak on Mount Lebanon, but in this they were mistaken. He found the species north of Latakia, in northern Syria, not far form the border with Turkey, so it is not understood why he chose the epithet libani (of Lebanon). Mouterde (1966) evidently had his nose put out of joint by Olivier’s choice of epithet and decried his cavalier approach to the niceties of geo-political distinctions. But this is not really fair: Olivier states clearly that he considered the oak to be Syrian, and refers to it as celui de Syrie (the Syrian one) (Olivier 1804). So why did he call it libani? It is possible he assumed the species also occured in Lebanon, where he had come from on his journey. He may have found a rare specimen in Mount Lebanon, or confused it with the leaves of Q. look, or assumed that it existed there due to the similarities in the composition of vegetation of Lebanon and the area where he found it (J. Stephan pers. comm.). Until recently, it had never been found in Lebanon, and most references state that it is not native there (le Hardÿ de Beaulieu & Lamant 2010; Avishai 2017; Plants of the World Online 2021). George Post reported having encountered it on the north-eastern slopes of Mount Lebanon in 1932, but subsequent searches could not confirm this. However, in a paper published in November 2020, Addam et al. reported that the species had been found in 2018 in the Shouf Biosphere reserve, in southern Mount Lebanon, so it appears Olivier may have been right all along.
This was described by Dippel (1892) as a cultivated, shrubby form with short, reddish-yellow petioles and relatively narrow leaves, 1–2 cm broad (compared to 2.5–3.5 cm broad that he gave for typical Q. libani), with up to 15 bristle-tipped teeth (compared to 9–13 that he gave for typical Q. libani) on each side. It is uncertain if it is still in cultivation; two trees under this name at the Sir Harold Hillier Gardens were 11 m × 34.5 cm in 2007 and 14.7 m × 44.8 cm in 2019 respectively (Royal Botanic Garden Edinburgh 1997). The photos are of trees in cultivation under this name, but their identities have not been confirmed.