We often recognise a tree from its leaves or bark.

This time, stand back and look at its shape.

A tree’s crown develops in response to the conditions in which it grows. Light matters, but so do wind, neighbouring trees, damage and the lie of the land.

There is a curious idea known as the ‘tick effect’.

In the Northern Hemisphere, the southern side of a tree generally receives more direct sunlight. Given enough space, branches on this side may develop differently from those facing north. Viewed from the east or west, the silhouette can sometimes resemble a tick.

It isn’t a reliable way to find south. Too many other things influence the shape of a tree.

But it gives you something to look for.

Find a tree with a clear crown. Stand far enough away to see its whole shape, then walk around it.

Notice which way the branches grow.

Do you see the tick?