Carpinus betulus

At first sight the hornbeam may be mistaken for the much commoner beech, which it resembles somewhat in form, bark, and leaf. Our drawings bring out the main points of difference; for comparison, beech is illustrated in Figures 34-37. Hornbeam ieaves, shown in Figure 27. are simpte and oval like those of beech, but have distincdy toothed edges, and a much stronger pattern of parallel veins. The bark, though smooth and grey as In beech, has a remarkable network of smooth metallic-blue stri-ations. seen on no other tree. Winter buds, though beech-like, are much shorter, and are in dined inward towards the twigs, instead of pointing outwards. The flowers and seeds differ markedly from those of beech, and show the hornbeam's close relationship to the birch tree, with which it is grouped in the family Betulaceae.

The male catkins are not seen until March, when they emerge from the buds and droop downwards. Each is made up of many didiasia, or short branches each bearing a large bract and a cluster figure 25

Winter twig of hornbeam; note how die buds hug the twigs (life size). Below: a single bud (X5).

of twelve stamens. Each stamen-group is really three flowers, consisting of four stamens apiece: each stamen is forked just below the anthers. The male catkins fall as soon as their pollen is shed

Female catkins are grouped, as our drawing shows, close to the tips of the twigs: they look rather tike shoot'buds. Each female dichastum consists of a long, slender pointed bract; at the base of this are set two flowers, each with two long styles, and six tiny hracteoles. As the fruits develop, the large bract disappears, but the little bracteoles enlarge enormously and form curious, papery, pale green wings. As there are three bracteoles to each flower, the result is a pair of fruits, each with a wing composed of three fused arms, A single flower with its wing, having one long lobe and two shorter ones, is seen in Figure 21 (bottom right), but the usual pattern is for the flowers to be paired, as in the main drawing.

The fruit of each flower is a one-seeded nut though this looks small to us it makes a good morsel for a hungry bird, and flocks of finches and tits frequent hornbeam trees in autumn to eat the seeds; squirrels and wood mice relish them too. Those seeds that escape attack are carried away by the wind, supported on their three-pointed wings. They lie dormant on the forest floor for IS months before they sprout

Hornbeam is native only to the south-east of Britain, having apparendy arrived too late to spread farther. You can find it in Kent and Sussex, along all the valleys of the Thames and its tributaries, and very locally in South Wales and a few other westerly districts. Elsewhere it is only seen as a planted tree. It yields a first-rate firewood, and in the past it was often cultivated in south-eastern England by the coppice or pollard methods that enabled repeated crops of poles to be cut without replanting. A typical pollarded tree is one which has been lopped at head height a cluster of branches then springs out after each lopping, safely above the reach of browsing catde and sheep. Pollard hornbeams are frequent in Epping Forest and Enfield Chase, north of London. In Kent the crop was usually coppiced, that is, cut at ground level. Left to itself, hornbeam forms a grand timber tree, up to 25m tall It is also very good for hedging; a hornbeam hedge holds its fawn-coloured faded leaves on the twigs all the winter through, so providing colour and shelter.

The wood of hornbeams is exceptionally hard and strong. This explains its name, which is an Anglo-Saxon one meaning 'horny (wooded) tree.' It was used in the past for ox-yokes, fitting across their shoulders so that they could draw heavy ploughs or carts. It was also employed to make cog wheels for watermills and windmills. as it wears smoothly for a very long time. For the same reason, it is still used in piano mechanisms. Today its mam use is in chopping blocks in butchers' shops, since it stands hard abrasive wear better than any other timber. But little hard timber is needed today, and hornbeam is now only planted for ornament


Flowering twig of hornbeam in late April just as die leaves open (xf). The drooping male catkins are made up of many dlchasia or flower groups.

Top centre: one dichasium. which is technically three flowers, is seen to consist of one bract and twelve stamens. Female catkins are seen near tip of twig.- a single one (X2) appears at top left. Bottom right one female dichasium, seen from within (X7) holds two flowers, with two long styles apiece, and six bracteoles.

Poison Fruits And Leaf Art Pictures

figure 27

Fruiting twig of hornbeam in October, showing typical leaves (xj), Each pair of fruits, holding two nuts attached to two three-lobed wings, arises from one dichasium. A single nut and its bract are shown at bottom right figure 27

Fruiting twig of hornbeam in October, showing typical leaves (xj), Each pair of fruits, holding two nuts attached to two three-lobed wings, arises from one dichasium. A single nut and its bract are shown at bottom right

Was this article helpful?

0 0

Post a comment