Quercus incana Bartram

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Credits

Article from New Trees by John Grimshaw & Ross Bayton

Recommended citation
'Quercus incana' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/quercus/quercus-incana/). Accessed 2024-10-06.

Genus

  • Quercus
  • Subgen. Quercus, Sect. Lobatae

Common Names

  • Bluejack Oak

Other taxa in genus

Glossary

flush
Coordinated growth of leaves or flowers. Such new growth is often a different colour to mature foliage.
pubescence
Hairiness.

References

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Credits

Article from New Trees by John Grimshaw & Ross Bayton

Recommended citation
'Quercus incana' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/quercus/quercus-incana/). Accessed 2024-10-06.

Tree, usually to 10 m, occasionally to 17 m, 0.7 m dbh, often forming thickets with thin, irregular crowns. Bark dark brown or black, becoming thick and corky, but broken into square plates. Branchlets brown or reddish brown and tomentose. Leaves deciduous (or semi-evergreen), 3–10 × 1.2–3.5 cm, ovate to elliptic or obovate, upper surface glossy and with sparse hairs along the midrib, lower surface densely tomentose and with longer (sometimes reddish) hairs in vein axils, 6–12 secondary veins on each side of the midrib, margins entire with one apical bristle, or occasionally a couple of weak lobes, apex acute to obtuse; petiole 0.2–1 cm long and tomentose. Cupules one (to two), sessile; saucer- or bowl-shaped, 1–1.8 × 0.4–0.8 cm, outer surface minutely pubescent, inner uniformly pubescent; scales acute to obtuse, tips tightly appressed. Acorn ovoid to subglobose, with one-quarter to one-third (rarely half) of its length enclosed in the cupule, 1–1.7 cm long, stylopodium prominent. Flowering March to April, fruiting September to October of the following year (USA). Nixon 1997, Sternberg 2004. Distribution USA: Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Texas, Virginia. Habitat Barrens, hammocks, dunes and upland ridges between 0 and 250 m asl. Typically on well-drained, sandy soils. USDA Hardiness Zone ~5. Conservation status Least Concern. Illustration Nixon 1997, Sternberg 2004. Cross-references B485, K90.

Bean (1976b) believed this species to be not in cultivation in Britain, and although it is now represented here it is unlikely to become widely grown. It seems to require hot summers and does not prosper in the cool climate of northern Europe: all the specimens seen in England have the appearance of being there against their wishes. Perhaps the most contented-seeming is a 4.2 m tree (2008) at the Sir Harold Hillier Gardens, in a sunny site on sandy soil with shelter behind it. Grown from a collection made in 1993 in Bienville Co., Louisiana, and planted in 1999, it is doing comparatively well. Slightly taller trees at Chevithorne Barton (4.5 m in 2008, planted in 1992, from Mallet Court Nursery) lack distinct leaders, and form a tangled top that looks more like an Elaeagnus than an oak. The general failure to thrive in northern Europe is regrettable, because the dense grey pubescence of Quercus incana is immediately recognisable and makes the tree distinct and attractive. The grey pubescence gives interesting colour effects as the bronze flush of new growth or the red autumn tints develop below it. It is much more impressive in the warm parts of the United States (Sternberg 2004). Plants of Q. incana have recently been distributed in continental Europe as Q. pumila Walter – a shorter, shrubby species (A. Coombes, pers. comm. 2008), which is in cultivation at the Hillier Gardens and elsewhere.