77. English Oak

Location: Between the Chemistry Building and Medicinal Garden, slightly east of Okanagan lane.

Historical Background: This introduced species is from Eurasia, and is now naturalized in the eastern United States. It is known for being one of the most characteristic British trees, its noble stature and vast size (in older specimens) has lent it an air of majesty, compounded by its use in such venerable projects as the paneling the the British House of Parliament and, historically, naval vessels. Oak wood hardens over time and is thus incredibly tough losing nothing to age. This tree thrives best in heavy clay soils (although it can grow in other conditions), and the bark may be used as a source of tannin. While they have the potential to live for thousands of years, the majority of those left especially in the British Isles are relatively young, the most impressive specimens felled long ago in the quest for firewood and building material. The British used the wood of these trees at an astounding rate, one sailing ship often took 2,500 trees to build. Fortunately they grow particularly fast in the first hundred years of life, although they do not begin producing acorns until at least 25 years of age. The largest known today has a circumference of 33 feet, and is estimated to be between 800 and 1000 years old. Currently several pathogens and insects threaten English Oaks in their native range.

Non-native

Native Range: Europe, North Africa, and Western Asia.

Identifying Features: Long graceful simple leaves with rounded lobes in pairs of 4 or 5. In open areas the crown is immense and open, with large heavy branches. In more wooded areas (or in some cultivars) the species grows with far more apical control. The acorns are about 1” (2.5cm) in length and usually in pairs, often carried on long stalks. Bark is dark grey and furrowed, becoming thicker with age.

Identifying Features In Depth:

1. Form: A large irregular tree with a domed spreading and open crown and large heavy branches which bear sprouts randomly. In shaded areas may demonstrate a higher degree of apical control. Can grow to a height greater than 80’ (24m) and easily achieve a diameter of greater than 3’ (0.9m).

2. Leaves: The leaves of this tree have small auricles (small ear-like projections at the base). Leaves are 2-5” (5-13cm) in length with 6-14 shallow and smoothly rounded lobes. The petiole is very short. The leaves are dark green above and far paler beneath.

3. Bark: Dark grey in color with irregular deep furrows. Bark becomes thicker and more furrowed with age.

4. Reproductive Bodies: Acorns are from ⅝-1” (1.5-2.5cm) in length, shaped like eggs with flattened bottoms, enclosed by a rounded cup. They are initially green turning brown with age, and are connected via a long slender stalk usually in groups of 2-5.