There are over six hundred species of oak in the world. In this article though, we’ll just take a look at five: Quercus robur, Quercus petraea, Quercus ilex, Quercus rubra and Quercus cerris. These are five of the most frequently grown oaks in Britain, with Q. robur and Q. petraea being the first and second most common, respectively.
To help distinguish between these species, we’ll take a look at their key identifying features, paying particular attention their leaf shape, autumn colour, and acorns.
Quercus robur (English Oak)
Leaves have deep, smooth, and rounded lobes. Smaller lobes appear at the base of the leaf.
The leaves grow in bunches and have a very short, or no, petiole.
Q. robur is deciduous; in autumn, leaves turn orange-brown.
Acorns have long peduncles and tend to grow on their own.
Bark is deeply fissured and grey-brown.
Buds are round, brown, with those at the ends of twigs growing in clusters.
Quercus petraea (Sessile Oak)
Leaves have round, smooth, shallow lobes, and grow on long petioles. The margins of the leaves are undulate and merge gradually into the petiole at their base.
Q. petraea is deciduous; leaves turn brown-orange in autumn.
Bark is deeply fissured and grey-brown.
Acorns are stalkless (sessile), and grow in pairs or clusters.
Quercus ilex (Holm Oak)
Q. ilex is evergreen.
Leaves are ovate and dark green to black. Their upper side is glossy, whereas their lower side is downy (covered in fine, soft hairs).
Younger leaves are spiny and resemble those of holly; older leaves have smooth and entire margins.
Bark is finely cracked.
Acorns are dark red-brown and rather small (around 2cm long). They have a pronounced pointed-tip and short peduncles.
Quercus rubra (red oak)
Deciduous; autumn colour is orange-red.
Leaves have long lobes which themselves have 1-3 teeth and a pointed tip. In spring/summer, leaves are dark green, glossy and have a pale, matted underside.
Acorns have short peduncles, and often grow in clusters. They take two years to ripen.
The bark of younger trees is smooth and silver-grey. More mature trees have vertical ridges that can be shiny and white.
Quercus cerris (Turkey Oak)
Leaves are thick, long and have irregular lobes: some lobes are rounded, whereas others are pointed and wavy. Leaves are glossy on the upper side, and felted on the lower side.
Acorns are large, orange at the base, and have a hairy cupule.
Bark is dark grey, and develops fissures and plates with age. Older trees may also have orange-brown fissures near the base.
The Herbaceous Fox 