The trunk of the Hornbeam is a dull grey colour, and it is marked with white spots. It is not round, as are most tree trunks, but looks as if it had been slightly flattened, and so made oval when it was young. The leaves are not unlike those of the Elm and the young Beech, and when the tree is young it is sometimes mistaken for one or other of these. But you will notice some differences if you look carefully. The Hornbeam leaf (2) is oval and tapers to a sharp point. It has strongly-marked veins running from the centre to the edge of the leaf, and these veins stand up like cord on the under-side of the leaf. You remember that the Beech leaf was smooth and glossy, and that the Elm leaf was rough and hairy? The Hornbeam comes just between the two: it is too rough to be a Beech leaf, and is also too pointed, and it is too smooth to be an Elm leaf. Besides, the two sides of the Hornbeam leaf meet exactly opposite each other on the leaf stalk, and in the Elm the one side of the leaf very often joins the stalk farther down than the other: the leaf is lopsided. The Hornbeam leaves have two rows of teeth round the edge, and in autumn they turn yellow, and this yellow colour changes into red-brown as the winter draws near. In sheltered places the leaves will hang on the branches all winter, till in spring they are pushed off by the young leaf buds. The Hornbeam has two kinds of flowers, which grow in catkins, and both are found on the same tree. The stamen catkins (3) come with the young leaves early in April, and they grow on those twigs which were produced last year. It is not possible to mistake the Hornbeam for either the Beech or the Elm if you see the flowers, for neither of these has hanging catkins like the Hornbeam. Each catkin is made up of many green scales covering the catkin loosely. These scales are broad and oval, and they end in a sharp point. Hidden at the foot of each scale lies a thick bunch of yellow-headed stamens with no petals and no sepals around them. These yellow stamen heads end in tufts of fine hairs, and they are filled with pollen dust. As soon as this dust is ripe the yellow heads burst and scatter it over the seed flowers which have been making ready to receive it. After this the stamen catkins shrivel, and they soon fall from the tree.