Quercus gambelii

Quercus gambelii, with the common name Gambel oak, is a deciduous small tree or large shrub that is widespread in the foothills and lower mountains of western North America. It is also regionally called scrub oak, oak brush, and white oak. The common and scientific names, Gambel oak and Quercus gambelii, were named after the American naturalist William Gambel (1821–1849).

Description

A small tree. It grows 9 m high and spreads 8 m wide. It loses its leaves during the year. It can spread from underground runners. It can form clumps. The leaves have 3-6 deep lobes on each side. There are fine hairs underneath. The fruit are oval acorns.

Edible Uses

The acorn was a staple food for several native North American tribes. It has a sweet flavour and is about 2cm long and wide. It can be eaten raw or cooked, dried and ground into flour for thickening stews, or mixed with cereals for bread. Where bitter tannins are present, they can be leached out by washing thoroughly in running water, though minerals are also lost. Whole seeds may take several days or weeks to leach; wrapping in a cloth bag and placing in a running stream is one method. Ground meal leaches faster. A taste test confirms when enough tannin has been removed. Traditionally, seeds were buried in boggy ground over winter and dug up in spring once most astringency had gone. The roasted seed makes a coffee substitute.

Traditional Uses

The acorns are ground into a meal. They are also boiled or lightly roasted. Parched acorns are used to make soup. The ground acorns are used to flavour meat. They are ground into flour, soaked in water and baked to make bread.

Medicinal Uses

Any galls that form on the tree are strongly astringent and have been used in the treatment of haemorrhages, chronic diarrhoea, and dysentery. The acorns have been eaten to increase sexual potency. The root bark is analgesic and cathartic — a decoction has been used to treat postpartum pain and to help facilitate delivery of the placenta.

Distribution

It is a temperate plant. It suits hardiness zones 4-9. Arboretum Tasmania.

Where It Grows

Australia, Central America, Mexico, North America, Tasmania, USA,

Cultivation

Prefers a good deep fertile loam which can be on the stiff side. Young plants tolerate reasonable levels of side shade. Tolerates moderate exposure, surviving well but being somewhat stunted. Prefers warmer summers than are usually experienced in Britain, trees often grow poorly in this country and fail to properly ripen their wood resulting in frost damage overwinter. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young. A slow growing shrub that often produces suckers and grows as a thicket, it occasionally makes a small tree. Seed production is cyclical, a year when good crops are produced is followed by several years of light production. The tree flowers on new growth produced in spring, the seed ripening in its first year. Hybridizes freely with other members of the genus. This species is notably resistant to honey fungus. A clumping plant, forming a colony from shoots away from the crown but with a limited spread.

Propagation

Acorns lose viability quickly if allowed to dry out. They can be stored moist and cool over winter, but are best sown as soon as ripe in an outdoor seed bed with protection from mice and squirrels. Small quantities can be sown in deep pots in a cold frame. Because plants develop a deep taproot early, they should be moved to permanent positions as soon as possible — seed sown in situ produces the best trees. Do not leave trees in a nursery bed for more than 2 growing seasons, as they transplant very poorly after that point. Suckers can also be divided during the dormant season.

Other Uses

A mulch of the leaves repels slugs and grubs, though fresh leaves should not be used as they can inhibit plant growth. Oak galls, produced by the larvae of various insects, can be harvested after the insect leaves and used as a rich source of tannin that also functions as a dyestuff. Seed cups serve as buttons. The wood is hard, heavy, and close-grained. Trees are generally too small to be of commercial use, but the wood is used locally for lumber and makes good fuel.

Notes

There are about 600 Quercus species.

Synonyms

Also Known As

Gambel’s oak, Shin oak, Utah oak

References (12)

• Beckstrom-Sternberg, Stephen M., and James A. Duke. "The Foodplant Database." http://probe.nalusda.gov:8300/cgi-bin/browse/foodplantdb.(ACEDB version 4.0 - data version July 1994) (Also as Quercus utahensis)
• Cundall, P., (ed.), 2004, Gardening Australia: flora: the gardener's bible. ABC Books. p 1124
• Elias, T.S. & Dykeman P.A., 1990, Edible Wild Plants. A North American Field guide. Sterling, New York p 231
• Glowinski, L., 1999, The Complete Book of Fruit Growing in Australia. Lothian. p 137
• Grandtner, M. M., 2008, World Dictionary of Trees. Wood and Forest Science Department. Laval University, Quebec, Qc Canada. (Internet database http://www.wdt.qc.ca)

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