Aloe+dichotoma

Aloe dichotoma: Quiver Tree media type="youtube" key="A6L3korqXb4?fs=1" height="385" width="480" align="center"

**__Scientific Classification__**


 * ** Kingdom ** || Plantae ||
 * ** Phylum ** || Angiosperms ||
 * ** Class ** || Monocots ||
 * ** Order ** || Asparagales ||
 * ** Family ** || Asphodelaceae ||
 * ** Genus ** || Aloe ||
 * ** Species ** || dichotoma ||

There are over two hundred and fifty thousand known species of angiosperms- more species of plants that in all the other plant divisions combined. New species are discovered almost daily. Angiosperms are all tracheophytes. Many can reproduce asexually by a broad variety of mechanisms, but they all reproduce by alternation of generations. The seeds they produce are enclosed in fruit formed by various flower parts. The sexual phase of alternation of generations allows genetic material to be recombined as a result of fertilization. Even the young produced by the same two parents can be very different from each other. Genetic variability within a species allows the species to survive various environmental forces it encounters. Young that are all identical may be resistant to attack from a particular disease. However, it is also possible that if they are not resistant, the species will disappear if that disease strikes. Genetic variability increases the possibility that some of the young have resistance and will survive. It is true that plants other than angiosperms have genetic diversity, but flowering plants have potential for limitless diversity and also produces seeds that are nature’s most reliable way of securing dispersal and survival of the next generation. Many of the plants we see are angiosperms. Trilliums, trout lilies, raspberries, thistles, clovers, asters, goldenrod, and apple trees are all obvious examples of angiosperms. What many people do not realize is that grasses, wheat, corn, beans, plus trees such as elms, maples, and birches, are all flowering plants. In these last examples, the flowers are easily missed because they are not large and colourful, and the fruit is easily missed because it is brown and thin instead of fleshy.
 * __ Description of Phylum: Angiospermae __**



The Quiver Tree (//Aloe dichotoma//) is probably the best known tree aloe found in South Africa and Namibia. It is also a succulent plant because it has the ability to store water in its stems and leaves. Quiver trees, are also known as Kokerboom, and are a species of aloe indigenous to South Africa, specifically in the Northern Cape region, and Namibia. They are referred to locally as “quiver trees” as the branches and bark are used by Kalahari San Bushmen to make quivers for their arrows. Known as Choje to the indigenous San people, the quiver tree gets its name from the San practice of hollowing out the tubular branches of Aloe dichotoma to form quivers for their arrows. In the past local people hollowed out the soft branches and used them as quivers for their arrows, hence the English vernacular name. Small animals make their homes between the leaves and in the corky trunk. The Pied Barbet is fond of enlarging holes in the trunk to construct its cosy nest, while Sociable Weavers build huge communal nests of grass in the crown, sometimes covering the whole tree. These Sociable Weavers' nests are shared by up to 400 birds, and often other species such as Pygmy Falcons and Redheaded Finches. A common phenomenon in the branches of these trees is the huge communal nest of weavers that live and breed by the thousands. Here their young and unborn are safe from predators such as snakes and jackals. The earliest record of //A. dichotoma// was made by Simon van der Stel (Governor of the Cape at the time) on his northward journey to the Copper Mountains in 1685. His record reads, "//Aloe arborescens//; its trunk is sometimes 12 feet high, and it has a beautiful, clear and copious sap from which excellent gumma aloes could probably be made in large quantities. Its bark is rather hard but the pith is soft, light and spongy. The branches of the trees are used by the natives (Bushmen) as quivers for their arrows. They hollow them out and cover the one end with a piece of leather and thus skilfully make from this tree, which they call //Choje//, a strong and serviceable quiver. October 15th". Large trunks of dead trees are also hollowed out and used as a natural fridge. Water, meat and vegetables are stored inside it. The fibrous tissue of the trunk has a cooling effect as air passes through it, a so-called natural fridge.
 * __ Intro to species __**



This distinctive tree aloe has smooth branches, which are covered with a thin layer of whitish powder that helps to reflect away the hot sun's rays. The bark on the trunk forms beautiful golden brown scales, but beware, the edges of these scales are razor sharp. The crown is often densely rounded as a result of the repeatedly forked branches; hence the species name //dichotoma// (dichotomous meaning forked). The blue-green leaves are borne on terminal rosettes, but in juvenile plants the leaves are ranked in vertical rows. The margins of the leaves have small triangular "teeth" for protection. Bright canary-yellow flowers appear during winter, which produce a copious supply of nectar that attracts a host of nectar lovers. Many birds including Mousebirds, Dusky Sunbirds and Pied Barbets enjoy a feast of nectar if they get to the flowers before the baboons do. //Aloe dichotoma// is an extremely tough tree that may reach an age of over 80 years and a height of approximately 7 metres.
 * __ U __****__ nique Morphological Features __**

The fibrous tissue of the trunk has a cooling effect as air passes through it. The branches and trunk of the quiver tree are filled with a soft fiber that can store water. In severe drought, the quiver tree seals off its own branches to save moisture loss through the leaves. In order to reduce water vapor loss, the tree does a very strange thing: self- amputation. It cuts off a leaf rosette, and seals the stump. The branch end looks like an amputated limb. The tree will survive with a reduced number of leaves, and put out new shoots when conditions improve.
 * __ Unique Anatomical/Physiological Features __**



In the desert which is this tree’s habitat, it is extremely hot and seldom rains. Few species can survive these harsh conditions- searing heat and little water. A remarkable quality of this tree is its ability to accumulate water in its leaves and corky tissue. For water storage, the quiver tree has green, succulent leaves and bloated branches. Leaves have thick rinds with very few pores, to minimize amount of water lost through evaporation. It has developed these adaptations because of the harsh climatic conditions in which it survives. Low air humidity, low soil moisture and intense sunshine levels have made it necessary to absorb even small amounts of moisture whenever the opportunity arrives. It has a superficial root system enabling it to absorb moisture quickly.
 * __ Adaptive Habitat Features __**

The Quiver Tree (// Aloe dichotoma //) is one of the best known desert plant species of southern Africa. Reaching heights of up to 10 metres, it is a conspicuous and striking component of the native landscape. Quiver Trees grow in arid regions of South Africa and Namibia. Within these two countries, the species is found predominantly in the west, and occurs throughout much of the Succulent Karoo Biodiversity Hotspot. Also, this species can be found growing on the rocky habitat of the hills along the Orange River. In some places it occurs in dense "forests", and good examples of these occur just south of Kenhardt and between Pofadder and Pella. The Doringberg hiking trails near Prieska pass by these gentle aloe giants, and close to 4 000 trees can be seen in the Kokerboom forest on the Kokerboom hiking trail near Kenhardt.
 * __ Range on Earth __**



The Aloe dichotoma is one of the largest Aloes. It is a single trunk tree aloe, the trunk is yellow between the leaves. The leaves are 8 to 12 inches long (20 to 30 cm), edged with small thorns. Its height can reach up to seven meters and has a lifespan of more than 80 years old. This species is more or less dormant in winter, keep it totally dry at or around 40°F (4°C). If freezing temperatures are expected, the trunk should be wrapped, since it is more frost sensitive than the leaves. This tree aloe has unremarkable yellow flowers in winter (the picture was taken at the Desert Botanical Garden in early January). **__ Angiosperm Life Cycle __**
 * __ Interesting facts __**
 * __ Cultural Practices: __**
 * __ Blooming Habits: __**


 * __ References __**
 * Reynolds, G. W. (1950). //The Aloes of South Africa// . Johannesburg: Trustees, Aloes of Galbraith, D. I., & Blake, L. (2001). Chapter 10: Fungi and Plants. //McGraw-Hill Ryerson biology 11// (p. 392). Whitby, Ont.: McGraw-Hill Ryerson.
 * Huntley, A. (n.d.). What is a quiver tree or kokerboom?. //Anderson// //Africa//. Retrieved November 12, 2010, from www.andersonafrica.co.za/kokerboom.html
 * Quiver Tree Forest Namibia. (n.d.). //Namibia// //Tourism Information and Travel Guide Safari Directories Maps All You Need To Know//. Retrieved November 14, 2010, from http://www.namibia-1on1.com/quivertreeforest.html
 * Reynolds, G. W. (1950). //The Aloes of South Africa// . Johannesburg: Trustees, Aloes of South Africa Book Fund.
 * Shapiro, L. (n.d.). Aloe dichotoma | EOLspecies. // EOLspecies // . Retrieved November 14, 2010, from http://eolspecies.lifedesks.org/pages/17371
 * Faucon, Philippe. "Kokerbom (Aloe dichotoma)." // Growing Tropical Plants in Phoenix //. Springhill Nursery, n.d. Web. 9 Nov. 2010. <http://www.desert-tropicals.com/Plants/Asphodelaceae/Aloe