Welwitschia - a dwarf tree that can flourish for up to 2000 years

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The Welwitschia mirabilis is a dwarf tree with a number of physical attributes that allows it to survive the arid conditions of the Namib Desert in southern Africa.

The Welwitschia has a very short trunk (approximately knee-high in a human) compared to other trees. The trunk is iron-hard and roughly five feet (or 1.5 meters) in diameter. Two long leaves grow from the base of the stem along the ground and can measure up to thirty feet or (9 meters) in length. The leaves grow at about six inches or (15cm) a year. A large part of the trunk (measuring about 9 feet or 2.7 meters) lies below ground level. The main (or tap) root grows deeper so it can reach water.

These plants have adapted to the arid and hostile conditions of the Namib Desert in Namibia where the rainfall is less than half an inch (or 1.3cm) a year as well as times when there is no rainfall for up to five years. The Welwitschia never grows more than sixty two miles (or 100 meters) from the Atlantic Ocean. The coastal fogs of the Namibia, which can be blown inland, contain water which the pores of these plants absorb. The pores close when the fog eventually disappears due to the heat of the Sun. The Welwitschia therefore differs from most desert plants which rely on an elaborate root system to collect water.

The survival techniques of the Welwitschia also include a division of genders with male and female plants that have cones instead of flowers. The seeds cannot germinate until it rains which is only intermittent. The first leaves (or cotyledons) of the seedlings are kept because the leaves contain reserves of food which can last for five years, when the next rainfall arrives. This another characteristic of these plants which differs from other plants who allow the first leaves to die.

The Welwitschia can live up to two thousand years which is approximately from the time of Christ until the present day. A Welwitschia that is only a few hundred years old is considered to be a juvenile. The appearance of these plants is that of an untidy heap of leaves. This is due to the two main leaves, which are on the ground level, becoming torn and frayed by the wind.

The Welwitschia is one of only a handful of species of plants which can survive the harsh and hostile conditions such as those found in the Namib Desert of Namibia in Africa.

Boojum tree (or fouquieria columnaris tree) - of the USA and Mexico

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The Boojum tree, or fouquieria columnaris tree, resembles a large altar candle and is also known as the "cirio" (meaning candle in Spanish). These plants have adapted to the desert conditions of rocky plains of the Baja California peninsula, Mexico by developing some unique characteristics, such as having thick waxy bark, that have allowed them to flourish and survive.

The Boojum tree has a large trunk (measuring up to three feet (or 1 meter) wide at the base) that can grow to a height of sixty feet (18 meters). The numerous short branches that sprout from the trunk are spiky and sharp to human touch and grow in a spiral pattern up the trunk. The trunk and branches are covered with a thick waxy bark and is the reason why the Boojum tree looks similar to a large altar candle. Pale yellow rounded flowers grow on top of the trunk if it rains in the early summer.

The thorny spines on the branches protect the Boojum tree as they deter grazing herbivores. Miniature leaves grow close to the trunk resulting in the total surface area being so small that these trees are hardly ever affected by the searing heat of the Sun. The pores contained in the waxy bark close in extreme heat. This process also protects the fleshy inner tissues of the tree. The tops of these trees are prone to injury by the wind and often have bizarre shapes.

The physical characteristics of the Boojum tree has allowed it to thrive and flourish in the Vizcaino-Magdalena desert of Baja California. Forests of these trees rise above the other ground-level vegetation of the desert. Boojum trees hold so much water that ranchers in the area will cut them down during droughts for their cattle.

The Boojum tree is a species of tree that has adapted very well to the arid environment of the Vizcaino-Magdalena desert they inhabit.

Kokerboom tree (or Aloe dichotoma) - the crowned heads of the African desert

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The kokerboom tree is a remarkable, dome-shaped tree because it is the only tree which can flourish and survive in the harsh and hostile regions of south-west Africa. No other species of tree exists in these regions.

The strong appearance of the kokerboom tree (Aloe dichotoma) is due the base of the trunk having a diameter of three feet (or 1 meter) and growing to a height of twenty-three feet (or 7 meters). The trunk forks halfway into two branches with each of these branches dividing again. This process seldom happens in flowering trees and gives the kokerboom tree its dome-shaped appearance. These trees may appear to be strong but on closer investigation, the streaky white trunk is actually slender with the bark peeling off.

The tips of the branches have clusters of leaves which are greenish-grey in colour. Bright yellow flowers appear amongst the leaves in June and July which attract insects and birds that come to feed on the nectar-rich flowers. Baboons will live and feed on kokerboom trees and have been known to strip them bare.

The kookerboom tree can live for approximately one hundred years and is able to flourish and thrive in its hostile environment by soaking up moisture from the sea mists that occur at night. The roots of the kokerboom tree, which are thin and fibrous, are responsible for absorbing any precious moisture from the rocky ground.

People from the local tribes, such as the Hottentots and Bushmen, traditionally use the branches to make holders for their arrows and have named these trees the "quiver" tree.

The kookerboom tree is a unique plant because it is the only tree that is able to thrive and flourish in the arid and rocky environment of the south-west regions of Africa.