Quercus pungens

Liebm.

Sandpaper oak

Fagaceae Edible: Gum, Seeds, Nut 374 iNaturalist observations

iNaturalist· cc-by-nc

Summary

Quercus pungens, commonly known as the sandpaper oak or scrub oak, is a North American species evergreen or sub-evergreen shrub or small tree in the white oak group. There is one recognised variety, Quercus pungens var. vaseyana, the Vasey shin oak. Sandpaper oak hybridizes with gray oak (Quercus grisea) in the Guadalupe Mountains of New Mexico and Texas.

Description

Evergreen shrub reaching 2 m tall. Flowers April to May. Monoecious and wind-pollinated. Grows in medium loamy and heavy clay soils across mildly acidic to basic pH ranges. Establishes in semi-shade or full sun, preferring moist conditions. Hardy to UK zone 7 and not frost tender. Tolerates strong winds but not salt spray.

Edible Uses

The seed is small, reported as up to 1cm long by one source and up to 22mm by another, and must be cooked before eating. It can be dried and ground into a powder to thicken stews or mixed with cereals for bread-making. Bitter tannins in the seed can be leached out by thoroughly washing in running water, though minerals are lost in the process. Either whole seeds or ground powder can be leached — whole seeds may take several days or weeks, and placing them in a cloth bag in a stream was a traditional method. Ground powder leaches more quickly. A simple taste test confirms when tannin levels are acceptable. Seeds were traditionally buried in boggy ground over winter and dug up in spring when most astringency had diminished. The roasted seed also makes a coffee substitute. A gum obtained from the bark can be used for chewing.

Traditional Uses

The gum is used for chewing gum.

This uses section is brief — help expand it

Medicinal Uses

Galls produced on the tree are strongly astringent and have been used to treat haemorrhages, chronic diarrhoea, and dysentery.

Distribution

It is a temperate to tropical plant.

Where It Grows

Central America, Mexico, North America, 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. The tree flowers on new growth produced in spring, the seed ripening in its first year. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young. Hybridizes freely with other members of the genus. Plants in this genus are notably resistant to honey fungus.

Propagation

Seed loses viability quickly if allowed to dry out. It can be stored moist and cool over winter, but is best sown as soon as it is 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 — seeds sown in situ produce the best trees. Trees left in a nursery bed for more than 2 growing seasons transplant very badly.

Other Uses

A mulch of leaves repels slugs and grubs, though fresh leaves should not be used as they can inhibit plant growth. Oak galls, formed by insect larvae, are a rich source of tannin once the insects have pupated and left, and can also serve as a dyestuff. A tan-coloured dye is obtained from the bark.

Notes

There are about 600 Quercus species.

References (3)

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)
Moerman, D. F., 2010, Native American Ethnobotany. Timber Press. p 464
Plants for a Future database, The Field, Penpol, Lostwithiel, Cornwall, PL22 0NG, UK. http://www.scs.leeds.ac.uk/pfaf/