Quercus oblongifolia Torr.

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Credits

Article from New Trees by John Grimshaw & Ross Bayton

Recommended citation
'Quercus oblongifolia' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/quercus/quercus-oblongifolia/). Accessed 2024-03-19.

Genus

  • Quercus
  • Subgen. Quercus, Sect. Quercus

Common Names

  • Sonoran Blue Oak

Other taxa in genus

Glossary

References

There are no active references in this article.

Credits

Article from New Trees by John Grimshaw & Ross Bayton

Recommended citation
'Quercus oblongifolia' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/quercus/quercus-oblongifolia/). Accessed 2024-03-19.

Tree to 10 m, 0.45 m dbh. Crown spreading, rounded, with wide-spreading branches. Bark with small, fissured, square plates, pale grey. Branchlets pale brown with stellate tomentum, though soon largely glabrous. Leaves evergreen, (2–)3–6(–8) × (0.5–)1–2.5(–3) cm, oblong to elliptic or lanceolate, upper surface dull blue-green or glaucous with sparse ephemeral stellate tomentum, lower surface with dense, loose glandular tomentum, 7–8(–10) secondary veins on each side of the midrib, margins entire and undulate, though with occasional teeth towards the apex, apex acute to rounded; petiole 0.2–0.5 cm long. Infructescence 0.8–1.5 cm long with one to two cupules. Cupule cup-shaped, 1–1.3 × 0.6–0.8 cm; scales acute, tuberculate towards the base of cup, grey-pubescent. Acorn ovoid or oblong, with one-third of its length enclosed in the cupule, 1.2–1.7 cm long, stylopodium short. Flowering April, fruiting August to October (USA). Nixon 1997. Distribution MEXICO: Chihuahua, Coahuila, Durango, Sonora; USA: Arizona, New Mexico, Texas. Habitat High grasslands, woodlands and canyons between 1300 and 1650 m asl. USDA Hardiness Zone 7. Conservation status Not evaluated. Illustration Nixon 1997; NT741.

Appreciated in the southern United States for its blue-green foliage, and tolerant of heat, drought and alkaline soil (Texas Native Trees 2008), this should be an ideal small or medium-sized white oak for gardens in the dry southern and southwestern United States. Pyramidal when young, it becomes crooked and picturesque with age. It is a favourite of Sean Hogan (pers. comm. 2006), in whose Portland garden a young tree is growing at a rate of 60 cm or more each year. It is grown in European collections, the largest at the Hillier Gardens being over 5 m tall (planting date uncertain, but prior to 1980).