Quercus robur leaves framing an autumn swamp cypress

In picture green oak leaves surround the red ones of a swamp cypress by a small mountain stream in the Eastern Cape during May. Both trees are exotics, but neither is evil. They won’t invade and they won’t steal all the water. They may grow tall or add value where few South African trees will make it. There is a useful balance in the issue of allowing exotic trees in South Africa.

The common oak tree, English oak or European oak has been actively introduced a few centuries ago in South Africa. It is indigenous in Europe, Western Asia and North Africa.

This tree is so widely established in cities, towns and rural places of South Africa, so often brings the useful shade spot far from water in our tree-poor country that few will quibble about the European oak as an accepted local feature in our parks and gardens. While locally not invasive, it is in many places our adopted summer shade tree from long ago under which people have social and cultural activities. It brings the comfort for outdoor events and surely has earned a position with the indigenous ones in a presentation on present-day South African trees.

Quercus robur, or the most common oak tree in South Africa, is a large, deciduous tree with broad, rounded crown, often reaching heights around 15 m or taller.

Mature trees have trunks with circumference around 4 m, although some European trees in their natural habitat reach much more. There is one in England with circumference of 12,2 m and even in northern Europe one in Latvia measuring 10,2 m.

Quercus robur is a long-lived tree, often lasting naturally for a few centuries. Some pollarded and specially treated trees in Europe are believed to be 1500 years old. The spreading and upright branches from the relatively short trunk are wide and tall, the dark grey bark furrowed and ridged on bigger stems.

The elliptic leaves on short stalks are roundly three to seven lobed. During autumn they become richly coloured, mainly in browns, but more.

Flowers appear as yellow green catkins during spring with the leaves, not conspicuous for long. The fruit is a stalked, hard, brown, oval acorn that is food to several mammal species and some birds. A young tree may take 20 years before bearing its first acorns.

Cultivated in temperate regions of many parts of the world, Quercus robur has escaped into the wild in many parts of the world (www.gardenia.net; Wikipedia).