|The Beech Tree (Fagus sylvatica)
| Form. Beech, Fagus sylvatica, is a large tree, reaching 30 to 40 m in height (occasionally
50 m) and 5.5 m in girth. Beech usually lives for 150 to 300 years, but coppiced
individuals may occasionally reach 550 years. There is almost always a single stem.
Chromosome number = 24. A stately tree with a large column-like bole, up to 42.5 m tall
with a canopy up to 40 m in diameter and trunks over 6 m in girth. Shed their lower
branches when growing in woods. Beech trees exhibit monopodial growth.
Leaves. The leaves are alternate and ovate (egg-shaped in contour) to elliptic and 4 to
10 cm long (sometimes growing larger in trees which have been trimmed) with petioles 5
to 15 mm in length. The leaf margins are wavy. In shaded branches, the leaves form a
monolayer with fewer and larger leaves per branch; whilst in sunny conditions the leaves
form multiple layers. Shaded leaves have fewer layers of photosynthetic palisade
mesenchyme cells. Sun leaves have longer petioles (possibly to increase movements in
the wind for better mixing of air layers to supply more carbon dioxide for photosynthesis).
The leaves are very tough on trees growing in the open, where trees are more likely to be
buffeted by the elements and subject to dehydration; more delicate when growing in
woods. The leaves twist on their stalks to face the Sun. The young leaves open by April
and are soft, pale and vibrant green at first, toughening and darkening with age. The
darker green Summer leaves form a dense canopy. The Autumn leaves display
spectacular colour changes, turning yellow, then orange, russet and copper. In the copper
beech, the leaves are a copper, red or dark purple colour due to accessory pigments that
shield the chlorophyll. Copper beeches are at an advantage in exposed places subject to
high levels of ultraviolet light, since the red pigment shields the chlorophyll from Sun
Bark. The bark is distinctive: smooth (sometimes slightly roughened), thin and silver-grey
bark (often tinged green by epiphytic algae). The distinctive buds are long (1-2 cm) and
fusiform (spindle-shaped) and reddish-brown in colour. The new twigs are dull
purplish-brown, turning greyer in their second year. The bark is only about 6 mm thick on
a trunk of 30 cm (one foot) diameter. Type 3 lenticels, in which loose nonsuberised tissue
alternates with compact suberised tissue with the compact tissue forming closing layers
and a very definite annual layering.
Flowers. Wind-pollinated. The tree is monoecious (having separate male and female
flowers on the same individual) with male and female flowers occurring on the same
branch. This tree is protogynous: female flowers mature first, in April, followed by male
flowers, so as to reduce the odds of self-pollination. The male catkins are in groups of 2
or 3 hanging downwards on slender drooping stalks and each is a tassel of about 15
greenish flowers. Each stalk bears 2 or 3 long and slender scale leaves They have 8-16
stamens and 4-7 perianth (sepal/petal or tepal) lobes.
The female flowers usually occur in pairs and each has three styles, an inferior ovary, and
4-5 perianth lobes. The pair is surrounded by a scaly cupule with 4 valves (consisting of
the involucre / whorls of bracts). The female flowers are bristly, oval balls borne on a stem
with protruding long slender styles and appear by May. The female flowers mature 2-3
days before the male flowers. The floral formulae are essentially the same as those for
Fruit. The fruit (beech mast) is an ovoid 3-angled nut (about 1 to 2 cm long) and is
edible. Usually a pair of nuts (derived from the usual paired female flowers) but
occasionally as many as 5 are enclosed in the cupule which is usually 2-5 cm long and
covered in prickly awl-shaped spines.
The woody bracts of the female flower form a rough, bristly brown husk that contains two
3-sided nuts which ripen by October. A full crop of nuts are produced every five years
and trees produce their best crops when over 50 years of age. The ripe husks split into
fall sections, exposing the nuts, whilst still on the tree, and then the whole falls and the
nuts detach from the bracts later. In historic times, the nuts were used as a food for pigs,
but they are quite edible and taste like a cross between hazel and almond nuts. In most
years, however, most of the nuts are empty shells, but in good years they are plentiful.
Twigs. Long pointed chestnut-brown buds grow on dark purplish winter twigs.
Habitat. Beech prefers well-drained soils with a pH between 3.5 and 8.5, such as
limestone, sandy/stony soils, shallow soils and sandstone. In base-rich soils it occurs
along with Mercurialis perennis (Dog's Mercury) and as the pH drops and exposure
increases it gives way to yew (Taxus baccata). In deeper, moister and more base-poor
soils it grows alongside Rubus fruticosus (blackberry) and holy (Ilex aquifolium). Native to
SE-England and continental Europe. Thrives on chalky soils, well-drained loams and
sandy soils, shade-tolerant.
Beech is susceptible to Spring frosts, but is otherwise hardy. Beech is very shade-tolerant
and 'dwarf' plants which are shaded may grow up rapidly to fill storm gaps left by
windthrown trees. There are a number of planted cultivars, including 'Purpurea' the
attractive purple or copper beech.
Wood. White to pale brown; diffuse porous (the diameter of the xylem vessels formed in
spring and summer are approximately the same). The rays may be up to 25 cells wide
and may be one mm or more in height. Red heartwood may be present. Beech wood is of
the diffuse porous type. In diffuse porous wood the early xylem vessels (those formed in
Spring) are no larger or only slightly larger than those formed later in the year (though
annual growth rings are still visible).
Roots. The roots are shallow and slow to grow into new soil, making the tree vulnerable
to drought and also to toppling or windthrow when growing on slopes. Adventitious roots
can be produced on branches which contact the ground, resulting in self-layering (growth
of a new tree where a living branch touches the ground). In trees which are broken or
partly uprooted, reiterative sprouts form: new shoots replace the parent axis by growing
vertically. The shallow roots are often visible for some distance from the tree on the
surface of the soil. The roots are short, slow-growing and bear many branches and so
utilise a small soil volume more effectively (the preferred soil types of beech trees are
often shallow soils).
Above: this beech tree was colossal! It looks as if two main stems have fused / grafted
Packham et al. 2012. Biological Flora of the British Isles: Fagus sylvatica. Journal of
Ecology 100: 1557–1608.
14th May 2016, updated: 30 May 2016