D. English Oak

The English oak (figure 3.6) is native to Europe, east Russia, south west Asia and north Africa.

This is an extremely long-lived tree, possibly surviving for over 800 years, and can grow to over 30 m. The fruit (acorns) grow on long stalks, or peduncles, hence the tree’s alternative name of the pedunculate oak. The acorns fall in October.

The male flowers are yellow catkins and the female flowers are tiny green globules, and these appear in May. Leaves are alternate (figure 3.5) and leaf-base is heart-shaped with auricles. Bark is grey-green and somewhat shiny at first, becoming thick, grey-brown and ridged.

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Figure 3.5 Leaves and acorns

ak trees are home to more species of animals than any other European tree, including 30 species of birds and over 250 species of insects (mostly moths). Oaks are prone to attack from tiny wasps, which cause different types of gall including currant, hop and spangle galls, and oak apples. Each part of the tree has its own associated wildlife.

English oaks have been exploited for timber, although they are still a common sight in the British countryside. It is planted for forestry, and produces a long-lasting and durable heartwood, much in demand for interior and furniture work. The wood is characterised by its distinct (often wide) dark and light brown growth rings.

E. Baobab

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Figure 3.7 African Baobab

aobab (figure 3.7) is the common name of a genus of eight species of trees, native to Madagascar (the centre of diversity, with six species), mainland Africa and Australia (one species in each). The mainland African species also occurs in Madagascar, but it is not a native of that country. Other common names include boab, bottle tree and monkey bread tree. Baobabs are distinctive trees, growing up to 25 m tall, and up to 7 m (exceptionally 11 m) in trunk diameter with an immense girth and a relatively small crown. The thick trunk serves to store water (with the capacity to store up to 120,000 litres of water) soaked up during infrequent rainy spells.

They are deciduous and lack leaves for as much as nine months of the year. The leaves are also common as a leaf vegetable throughout the area of mainland African distribution, including Malawi, Zimbabwe and the Sahel. They are eaten both fresh and in the form of a dry powder. In Nigeria, the leaves are locally known as kuka, and are used to make kuka soup. The dry pulp of the fruit, after separation from the seeds and fibers, is eaten directly or mixed into porridge or milk. The seeds are mostly used as a thickener for soups, but may also be fermented into a seasoning, roasted for direct consumption, or pounded to extract vegetable oil.The tree also provides a source of fibre, dye and fuel.

The bare branches and thick trunk gave rise to the African legend that God uprooted the tree in a rage and planted it upside down, with the roots pointing to the sky. Baobabs are one of the longest-lived trees in the world, and some of the largest specimens are thought to be as much as 3,000 years old. The pendulous waxy white flowers have an unpleasant smell and open at night. They are pollinated by fruit bats and flies. The large fruit grows up to 24 cm long, and are sometimes known as monkey bread.

These trees have many uses. The fruit pulp is made into a drink and is used as a remedy for many diseases; and the leaves are eaten as a vegetable. The outer bark is used as a fabric after being softened and pounded, and the inner bark is twisted into rope.