Lushootseed Name: čaʔadᶻac (pronounced ch-ah-dawtz)

Also called the Oregon White Oak

Location: Southeast corner of Benson hall, towering above the patio.

Summary: The only oak species native to Washington State or British Columbia, Quercus garryana trees are a keystone of their native ecosystems. A type of White Oak, its deeply lobed leaves have rounded tips. The tops of these deciduous leaves are shiny green, the bottoms paler and slightly hairy. In their 500-year lifespan this tree can produce a canopy which frequently rises to 80’ in height and trunks with diameters in excess of five feet. 

The vast cultural importance of the Oregon White Oak lies in its barrel-shaped acorns, which are about an inch in length, capped by a shallow cup. These nuts are a traditional food of the Coast Salish people in our region, and of every other Indigenous Nation in the species’ home range. Acorns are rich in fat, proteins, and carbohydrates, and due to a high tannin content can be stored for years. While many argue that agriculture is the prerequisite to the establishment of non-nomadic cultures, there is ample evidence that the same level of long-term stability may be supplied by the Oak. Acorns are produced in abundance, as much as 1,000 pounds per acre every few years. White Oaks in our area were tended with great care to encourage continued persistence and high nut yield. The arrival of acorns in the Pacific Northwest was likely at least in part facilitated by humans thousands of years ago. Oak woodlands have traditionally been managed by Native Americans with prescribed fire, a practice which not only encourages continued dominance of the Oregon White Oak, but also supports a huge diversity of useful understory plant species and animals. Unfortunately, with the colonization of the region by Euro-Americans, these traditional practices have been repressed and these ecosystems have suffered major declines.

The wood of Quercus garryana has little commercial value today (though it was used as a hardwood lumber until the early 20th century), but it has nevertheless lost a large portion of its native habitat in Washington and Oregon due to development. Additionally, fire suppression implemented by Euro-American colonizers has caused further loss of habitat due to increased growth of conifers, which shade out smaller deciduous trees like oaks. Over 95% of the original Oak woodlands present in precolonial times in our region have now been lost. These trees have great potential as city trees, with strong wood, drought tolerance, and a love of the more open spaces present in most urban environments.

Historical Background:  The Coast Salish peoples soak the acorns to remove tannins before eating. The Saanich used the bark for medicine against health conditions like tuberculosis. The wood is difficult to season without warping, so it has no commercial value. However it has been used experimentally in Oregon for creating casks for aging wine. This species has experienced major reductions in its native ecosystems in absence of the careful land management practiced by many indigenous nations. These trees rely on frequent low intensity fire to keep out conifers, a process which also promotes excellent food for human in the form of animals and plants which thrive in the resulting oak savannah habitat. The killing and removal of indigenous peoples by Europeans and conversion of much of the oak savannah to agriculture has caused significant loss in Pacific Northwest populations of the tree. A fascinating population east of the Cascades represents one of the limited examples of a broadleaf deciduous species growing as a dominant member of the forest on that side of the mountain crest!

Native

Native Range: From B.C., Washington, Oregon, to California

Identifying Features light: This tree is the only oak native to Washington state or British Columbia, however, habitat loss due to land conversion for human uses has made it far more difficult to see in the wild here. As a white oak, it exhibits the classic deeply round-lobed deciduous leaves, a shiny light to dark green above, a paler and hairy beneath, up to 5’ (12cm) in length. Bark is light gray and develops thick furrows and ridges early in life, supporting a trunk growing to about 80” (25m) with heavy limbs and low apical control. As an oak, the species also produces acorns, nutlike seed containers smooth and barrel shaped, ending in a tip on one end and capped by a rough cup where they meet the branch. Garry oaks may live as much as 500 years.

Identifying Features In Depth (for app):

1. Form: Large and spreading when the environment allows, heavy-limbed and broad, up to about 80” (25m) in height. They have been known to obtain trunk diameters greater than 8 feet.

2. Leaves: Leaves are deciduous and grow alternately. They are deeply lobed (rounded), about 5’ (12cm) in length. The top achieves a shiny dark green in color, with the bottom greenish yellow and sprouting small hairs. In spring they are a light green and in fall turn a yellow-brown before falling.

3. Bark: Light grey in color and becoming thickly furrowed and ridged even early in life.

4. Reproductive Bodies: Male reproductive bodies appear as hanging catkins as leaves appear. Female flowers appear in similar hanging clusters or single flowers and give rise to barrel shaped acorns tapering to a tip and capped by a shallow rough cup. Acorns grow to a little over 1’ (3cm) in length and are mature in fall.