What Tree? Pedunculate Oak

What Tree? Pedunculate Oak

Pedunculate Oak (Quercus robur)

This month we focus on a tree that needs little introduction. Nearly everyone recognises the iconic leaves of this tree species, and a lot of people have fond memories of playing, foraging or climbing oak trees. If you’re not lucky enough to have these memories, it’s never too late to start.

The Pedunculate oak is also commonly known as English/European oak, or Common oak. It is native to the UK and is the most common tree species in the UK. It is found in woodlands, hedgerows, parklands and across the majority of urban areas too. One of the most famous Oak trees is the Royal Oak. It is believed that this is where King Charles II hid from the Roundheads after the Battle of Worcester (1651) during the English Civil War.

The name originates from the Latin Quercus, meaning oak, and robur meaning hardwood. The phrase pedunculate refers to ‘a structure that has a peduncle (a stalk or stem) or is attached to another structure by a peduncle’.

This is a long lived species and trees can live for over 1,000 years. It is thought that the oldest Oak in the UK is the Major Oak. This is found in Sherwood Forest and according to legend was used by Robin Hood and his Merry Men.

This species supports a great variety of insects, fauna and flora. An individual mature oak tree can support over 250 different species. The deadwood of this species is especially important for providing niche habitats. This is because the deadwood often persists in the crown for extended periods, whereas in other species with weaker wood, the dead limbs are shed relatively quickly after death. In addition, as trees age new habitats are formed. These can consist of exposed bark, cavities, broken limbs, hollows, fungi etc.

Ancient Oak Tree

Ancient Oak Tree

Oak is highly sought after for timber. The wood is extremely hard and durable. It is still used in the construction of buildings and furniture making.  It was historically used to make the ships for the British Royal Navy and the ‘Heart of Oak’ is the official march of the Royal Navy. The timber is also used for carving, flooring, barrel making and is an excellent source of firewood.

While the timber provides a valuable commodity, other parts of the tree have been used for centuries too. The foliage of the oak tree has been used as animal fodder for centuries and oak trees were historically managed as pollards. This would ensure a sustainable source of animal feed, timber product and firewood, which could be harvested every 10-15 years. The tanning found in oak bark has been used to tan leather since Roman times.

The oak tree is steeped in mythology and symbolism. The tree is a symbol of strength and the leaf shape has been used by numerous organisations (including National Trust and Woodland Trust). This species has historically been associated with royalty. Historical records indicate that crowns of oak leaves were worn by Roman Emperors. It was also associated with Greek, Roman, Nordic and Celtic gods. In these cases, they were considered sacred symbols of Zeus, Jupiter and Thor, respectively. Druids not only used the timber of this tree as wands/staffs, but also performed rituals and ceremonies in oak groves. Even acorns were also carried by people to bring good luck and good health.

Appearance and Identification

This is a large deciduous tree that can grow to 30 m tall. The canopy is often broad with large lower branches.

Leaves are generally between 6-10cm long and have 4-5 irregular, deep lobes and two tiny lobes at the leaf base. The leaf stalk is short to non-existent.

Male catkins are yellow, each around 6cm long and grow in rows, hanging down from the branch in a curtain. The female flowers are tiny with fine filaments protruding to catch the pollen. These later become the acorns. Acorns are 2-2.5cm long. Young acorns are vibrant green, turning a dark brown as they ripen, before being released from the acorn cup.

For winter identification look for rounded buds in clusters at the end of the branch tip. Each bud will have more than three scales. These can sometimes loosely resemble pigs’ trotters.

This species is often confused with Sessile oak (Quercus petrea). The main difference is that Pedunculate oak has short leaf stalks and long stalks which bare acorns. Whereas Sessile oak is the opposite, with long leaf stalk and virtually no stalks associated with the acorn cups.

In addition to the above, this species can be confused with Turkey oak (Quercus cerris). The key differences are that this species have longer leaves, with more lobes which are often irregular in size and shape. Furthermore, the buds and acorns cups will have twisted ‘whiskers’.

Propagation and Control

The tree is tolerant of a range of soil types and climatic conditions, although thrives in fertile and moist soils. It is frost resistant and exposed growing locations. Additionally, mature trees can endure flooding. This species is also tolerates shady environments, which means that it is suitable in woodland planting. Due to its overall hardiness, lifespan and habitat value it is a common species in both rural and urban planting.

The tree is relatively hardy and while susceptible to a range of fungal pathogens, can often survive for many years before the structural integrity warrants the trees removal. However, this species is susceptible to pests and pathogens. These are Oak Processionary Moth (OPM) and Acute Oak Decline (AOD).

OPM is a non-native pest that was found in 2012 in London. This species defoliate trees which can drastically impact the physiological function of the tree. The caterpillars also pose a risk to people and animals as the hairs are toxic. They cause irritation to skin and eyes and can cause serious respiratory problems if inhaled. Management of this species is ongoing, however a gradual spread across London boroughs, Surrey and Berkshire is evident.

AOD is a complex disease involving several casual agents. It was discovered in the UK in the late 20th century. It mainly affects pedunculate and sessile oaks but can be found in other oak species. Researchers believe that AOD could occur due to environmental conditions. It typically affects older trees and is identified by dark bleeds on the stem. There can also be D-shaped exit holes from the jewel beetle on the stem. The canopy will generally look thin and in decline. Research into this disease complex is on-going.

Source and Reference Materials

Information detailed in this post has been obtained from the author’s own knowledge and photographic library where possible. Additional source of information and photographs include:

More, D & White, J. (2013). Illustrated trees of Britain and Europe. Domino.

Van den Berk, B.V. (2004). Van den Berk on Trees. Van den Berk Nurseries.


Woodland Trust

Forest Research