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Quercus garryana - Garry Oak



"Garry oak (Quercus garryana) ecosystems are among the most endangered in Canada. Only an estimated 1–5% of the 1850s distribution remains in a near-natural state, providing habitat for more than 100 species considered at risk either nationally or provincially. Although habitat fragmentation and isolation threaten the long-term viability of Garry oak–associated species, all habitat remnants have been degraded by exotic species of plants and animals, and many suffer from the effects of fire suppression." [Apostol RPNW]


Food Uses

Other Uses

Medicinal Uses


General Deciduous Tree growing to 18 m (59ft) by 10 m (32ft) at a slow rate.PFAF-1 Often small and shrubby. Light grey bark (IFBC)E-flora with thick furrows and ridges. PCBC2004
Flowers Monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by Wind.PFAF-1 "Inflorescence of tiny inconspicuous male and female flowers".(IFBC)E-flora-1 The flowers are yellow.(USDA)E-flora-1 "male flowers in hanging catkins, female flowers single or in small clusters".PCBC2004
Fruits 1-seeded Acorns. Egg-shaped to nearly round. Bumpy.(IFBC)E-flora-1 " shallow, rough-surfaced cups...".PCBC2004 Matures in 2 years.Hitchcock&cronquist
Leaves Alternate, deciduous.(IFBC)E-flora-1 Deeply round-lobed oak leaves.PCBC2004 "...5-13cm long. (occasionally longer)...and usually shiny above, pale or rusty beneath with fine pubescence."HNW
Habitat Dry grasslands and rock outcrops in lowland.(IFBC)E-flora-1 The plant can tolerates strong winds but not maritime exposure.PFAF-1 "...sometimes found on deep, rich, well-drained soil". PCBC2004
Range SE Vancouver Island & the Gulf islands. South to California.(IFBC)E-flora-1
Status Native.E-flora-1
Ecological Indicator Shade-intolerant. "Occurs in maritime to submaritime summer-dry cool mesothermal climates on very dry to moderately dry soils;...Usually forms open-canopy stands on water-shedding (rock outcrops) sites. Its calcium-rich bark supports corticolous moss communities."(IPBC)E-flora-1
Similar Species In B.C. "...most easily confused with the introduced English oak (Quercus rubur)." "...In English oak, leaf lobing is shallow, less than halfway to the midrib, while in Garry oak lobing often extends more than halfway to the midrib." Hybridization can make oaks difficult to differentiate.E-flora-1 Hybrids are less of a problem in the Pacific Northwest than in southern Oregon and California, where several species are present. PWOBC


Quercus Sp.; Leached acorns contain from 5 - 20% fat, 2- 5% protein, 50 - 70% carbohydrate and lots of minerals.Tozer UWP Analysis of acorn meal has shown it to be 65% carbohydrates, 18% fat, and 6% protein. Nyerges

Quercus garryana Nuts: 9g water, 3.9g protein, 4.5g fat, 68.9g carbohydrates, 12g fiber, 1.8g ash per 100g fresh weight. [Turner&Kuhnlein]


"Lime tolerant (188). Young plants tolerate reasonable levels of side shade(200). Tolerates moderate exposure, surviving well but being somewhat stunted(200).... A slow-growing and drought tolerant tree(188, 229), it can live for 500 years(229). Seed production is cyclic, with a year of high production being followed by 2 - 3 years of lower yields(229). The tree flowers on new growth produced in spring, the seed ripening in its first year(200, 229). Intolerant of root disturbance, trees should be planted in their permanent positions whilst young(11). Hybridizes freely with other members of the genus(200). Plants in this genus are notably resistant to honey fungus(200)." PFAF-1

"White oak communities, Franklin and Dyrness reveal, come in several varieties, each named for the most prevalent understory shrub. These communities are called white oak/hazelnut, white oak/serviceberry, and gulp white oak/poison oak, which unfortunately is all too common around here. Each community contains a dozen or more associated plants...The tree also takes a decade or more to bear acorns..." [Hemenway GG]

Fire Regime: "Kalapuya and other local Native American groups were some of the first people to shape Willamette Valley ecosystems to meet their needs. Prior to European settlement they used fire as a management tool to maintain gardens of camas (Camassia quamash), a native prairie plant whose starchy bulb was a food staple, and to foster the growth of tarweed, grasshoppers, nut and berry plants, and bracken fern rhizomes (Agee 1993; Boyd 1999). They also set fires to herd deer for hunting. Oregon white oak (Quercus garryana) is adapted to fire in ways that other species are not. Its thick bark protects the delicate cambium, and dormant buds are located low on the root collar below the soil surface so they can sprout even after fire (Tveten and Fonda 1999). The fires the Kalapuya set thinned the understory of the oak woodlands and savannas, maintaining the stands’ open structure, enhancing tree vigor and seedling regeneration, and increasing mast crops for consumption by both humans and game (Agee 1993, 1996; Boyd 1999; Peter and Harrington 2002; Van Lear and Brose 2002). The fires also limited infestations by invasive plants and acorn-boring insects (Anderson 2005). The net effect of Kalapuyan management was to create an overstory of widely spaced, large-crowned Oregon white oak trees with an understory of shrubs and perennial native grasses (Agee 1990)." [Egan HDER]

[Hemenway GG]

''Burning was in the fall of the year when the plants were all dried up when it was going to rain. They’d burn areas when they would see it’s in need. If the brush was too high and too brushy it gets out of control. If the shrubs got two to four feet in height it would be time to burn. They’d burn every two years. Both men and women would set the fires. The flames wouldn’t get very high. It wouldn’t burn the trees, only the shrubs. They burned around the camping grounds where they lived and around where they gathered. They also cleared pathways between camps. Burning brush helped to save water. They burned in the valleys and foothills. I never heard of the Indians setting fires in the higher mountains, but don’t take my word for it. (Rosalie Bethel, North Fork Mono, pers. comm. 1991)'' [Anderson TTW]



Fagaceae - Oak Family [E-flora]
Evergreen or not.
Leaf: stipules small, generally early-deciduous.
Staminate inflorescence: catkins, 1–several, pendent, slender, proximal on twig.
Pistillate inflorescence: in upper leaf axils, short-stalked; flower generally 1.
Staminate flower: stamens 4–10.
Pistillate flower: calyx minute, generally 6-lobed; ovary enclosed by involucre.
Fruit: nut 1, partly enclosed by cup-like involucre (cup) with appressed scales (nut and cup = acorn); scales tubercled to not; mature years 1 (on younger stems) or 2 (on older stems). 2n=24.
± 600 species: northern hemisphere, to northern South America, India. (Latin: ancient name for oak) [Manos et al. 1999 Molec Phylogen Evol 12:333–349] Many named hybrids; those (3) treated here form widespread populations; most others occur as single individuals, and some but not all of these are mentioned here, under the first parent treated (alphabetically). Reproduction of many species declining due to habitat degradation or loss as well as disease.
Unabridged references: [Manos, P. S., Doyle, J. J., & Nixon, K. C. 1999. Phylogeny, biogeography, and processes of molecular differentiation of Quercus subgenus Quercus (Fagaceae). Molec Phylogen Evol 12: 333–349.][Jepson]

Local Species;

  1. Quercus garryana - Garry oak [TSFTK][PCBC][E-flora]
  2. Quercus robur? - English oak [E-flora]

Uses of Related Sp.

"All acorns are good to eat. Some are less sweet than others, that's all. But the bitterness that is prevalent in different degrees is due to tannin....The oaks may be separated into two great groups: the white oaks and the red oaks. The acorns of the former are the sweet ones....Indians leached their bitter acorns in a number of ways. Sometimes the acorns would be buried in swamp mud for a year, after which they would be ready for roasting and eating whole. Other tribes let their shelled acorns mold in baskets, then buried them in clean freshwater sand. When they had turned black, they were sweet and ready for use. " Angier FFWE "Many of the sweet acorns borne by the White Oak group are not at all unpleasant eaten raw. Gibbons SHH "Only the scrub Oaks were not generally used by the Indians, though even these were taken in times of acute shortage of other food." EUCP

Quercus Sp.
It has been said that the Oaks produce more nuts annually than all other wild and cultivated nut trees combined. Tozer UWP


The information presented on this site is provided for educational purposes. Self diagnosis and treatment, without due diligence, could be harmful and is not encouraged. Some information & images may be copyright. Every effort has been made to present the information in the spirit with which it was originally presented. Some data has been omitted for legal and/or practical consideration. There is some data not covered in the scope of this project, including, but not limited to, cell culture and large-dose animal studies. I have made comparisons and links between related species which may later prove erroneous. I have not verified the information for accuracy and I accept no responsibility for its authenticity. Many of the plants presented are poisonous, have poisonous properties, or could cause illness through misuse, allergic reaction, drug interactions and environmental contaminants. Please use caution and mindfulness when harvesting plants for any use.

Page last modified on 31-10-2016