The great oaks of the North

Al Lowe
Science Correspondent

We have all heard about the sturdy oaks. For centuries, the Royal Navy proudly marched behind the band playing ‘Hearts of Oak’.
Well, there are a great many oaks in the world, over 200 species in all. And not all of them are sturdy. Some are spindly little trees, and some are only shrubs, but many are the trees of great age and size, which are the ‘mighty oaks’ of song and legend.
In North America, there are about 70 species of oak, but out of all of these, only two are found in Northern Ontario. Even these two are found only in the southern part. They are the Bur Oak and the Red Oak.
The Bur Oak (or Mossy Cup Oak) is generally a medium sized tree of 70 or 80 feet, but it can and does reach a height of 170 or 180 feet, with a diameter of 6 or 7 feet. Quite a substantial tree!
Incidentally, La Verendry’s records show that the banks of Rainy River were covered with thick stands of large oaks, when he first saw them in 1731. Remember that when the white man first arrived in North America, the trees had been growing undisturbed for centuries. Oaks cut in Pennsylvania in the 1830s were recorded as being over 400 years old.
The Bur Oak is a nice, well-shaped tree. Sturdy and hardy, it can stand up to smoke and other atmospheric pollution, which makes it a good shade tree for cities and papermill towns. Its acorns are fairly large. The ‘cup’ of the acorn is always covered with thick hairs in a fringe, which gives it its other common name. The cup is always large, covering half or more of the acorn. Hence its scientific name ‘Quercus macrocarpa’, which simply means the ‘oak with the large cup’.
Bur Oak is widespread, growing well out into the prairies, as well as in almost all of eastern North America.
Our other oak is quite different. It is the Red Oak, Quercus rubra, with sharp pointed leaves, and short, stubby acorns. This is a fairly small tree, about 60 feet high, perhaps 100 feet in the very best locations. Here in the north, it is quite small. Look for it on rocky ridges, or on rocky islands in our lakes.
Out in the open, the Red Oak becomes a well-shaped rounded specimen. Because of its colour, shape and hardiness, it is quite widely planted in Europe as a specimen tree. We bring trees from Europe and they import some of ours.
These are our two oaks. They both turn a metallic, bronzy red in the fall.
The leaves are quite different, with the Red being very sharply pointed, and the Bur being deeply lobed and rounded.