Coffea - Coffee Tree
( Coffea arabica). Flowers and fruits
Coffea - Coffee Tree - Coffea arabica
Coffea is a genus of flowering plants whose seeds, called coffee beans, are used to make
coffee. It is a member of the family Rubiaceae. They are shrubs or small trees native to tropical and southern Africa and tropical
Asia. Coffee ranks as one of the world's most valuable and widely traded commodity crops and is an important export product of several
countries, including those in Central and South America, the Caribbean and
In total, there are 125 coffee species, which occur naturally in
Africa, the Indian Ocean Islands, (Madagascar, Comoros, and the Mascarenes), southern
Asia, south east Asia and Australia. Several species of Coffea may be grown for the
seeds. Arabica and Robusta coffee are the main beverage species, with a small percentage of Liberica coffee
(Coffea liberica) grown for commercial purposes. Coffea arabica accounts for 75-80 percent of the world's coffee
production, while Coffea canephora accounts for about 20 percent. Other species in East Africa and Madagascar are sometimes used locally to make coffee on a very small
Coffea arabica is native to northeast Tropical Africa
(Southern Ethiopia, South Sudan (Boma Plateau), the mountainous regions of Yemen; and possibly East Tropical Africa
(Kenya, Mt Marsabit). It is sometimes naturalised in tropical areas. Arabica coffee grows at 950 m to 1,950 m above sea
level. It is also known as the "coffee shrub of Arabia",
"mountain coffee", or "arabica coffee". C. arabica is believed to be the first species of coffee to be
Wild plants grow between 9 and 12 m (29 and 39 ft) tall, and have an open branching
system. Én plantations they are usually pruned to take the form of a small
shrub ( 2 to 8 m tall). The leaves are opposite, simple elliptic-ovate to oblong, 6–12 cm (2.4–4.8
in) long and 4–8 cm (1.6–3.2 in) broad, glossy dark green. The flowers are
white, 10–15 mm in diameter and grow in axillary clusters. They are hermaphroditic and
sweet-scented, the corolla white, tubular, normally with 5 lobes. The fruits are drupeó, 10–15 mm in
diameter, usually red but sometimes yellow or purple at maturity. The outer layer is
soft, edible and sweet-tasting, containing two or sometimes one 'seed' (the coffee
seeds) — actually a seed encased in a hard, almost crispy outer layer which together forms a structure known as a
pyrene; this outer layer is removed by milling. The seed itself is pale fawn or brown
(dark brown only after roasting) and has a characteristic groove on its inner
surface, which curls round inside the seed.
C. arabica takes about seven years to mature fully, and does best with 1.0–1.5 meters
(about 40–59 inches) of rain, evenly distributed throughout the year. It is usually cultivated between 1,300 and 1,500 m
altitude, but plantations grow it as low as sea level and as high as 2,800 m.
The plant can tolerate low temperatures, but not frost, and does best with an average temperature between 15 and 24 °C (59 and 75 °F). Commercial cultivars mostly only grow to about 5 m, and are frequently trimmed as low as 2 m to facilitate
harvesting. Unlike Coffea canephora, C. arabica prefers to be grown in light
Two to four years after planting, C. arabica produces small, white, highly fragrant
flowers. The sweet fragrance resembles the sweet smell of jasmine flowers. Flowers opening on sunny days result in the greatest numbers of
berries. This can be a curse, however, as coffee plants tend to produce too many
berries; this can lead to an inferior harvest and even damage yield in the following
years, as the plant favours the ripening of berries to the detriment of its own
On well-kept plantations, overflowering is prevented by pruning the tree. The flowers only last a few
days, leaving behind only the thick, dark-green leaves. The berries then begin to
appear. These are as dark green as the foliage, until they begin to ripen, at first to yellow and then light red and finally darkening to a glossy deep
red. At this point they are called “cherry” and are ready for picking.
The berries are oblong and about 1 cm long. Inferior coffee results from picking them too early or too
late, so many are picked by hand to be able to better select them, as they do not all ripen at the same
time. They are sometimes shaken off the tree onto mats, which means ripe and unripe berries are collected
Arabica coffee’s first domestication in Ethiopia is
obscure, but cultivation in Yemen is well documented by the 12th century. According to
legend, human cultivation of coffee began after goats in Ethiopia. Á goatherd noticed that his goats bacame unusually alert and frisky after eating the leaves and fruits of the coffee
tree. People sampled the beans and determined that they might be useful for keeping people awake during evening religious
ceremonies. In Ethiopia, people in some locales still drink an herbal tea
made from the leaves of the coffee tree.
The first written record of coffee made from roasted coffee beans comes from
Arab scholars, who wrote that it was useful in prolonging their working hours.
The Arab innovation in Yemen of making a brew from roasted beans, spread first
among the Egyptians and Turks, and later on found its way around the world.
Other scholars believe that the coffee plant was introduced into Yemen from
Abyssinia, based on a Yemeni tradition that slips of both coffee and qat were
planted at 'Udein ('the two twigs') in Yemen in pre-Islamic times.
Coffee became a popular drink in Europe from the seventeenth century
onwards, being imported from plantations established first by the Dutch in Ceylon
(now Sri Lanka), Java, and later from plantations in Brazil and the West Indies established in the eighteenth
century. Much of the world’s Arabica coffee is produced in Latin America.
The stimulating effects of coffee are largely due to the alkaloid caffeine contained in the
seeds. As well as a beverage, coffee is used for flavouring foods and
confectionery. The beans are also a commercial source of caffeine, a by-product of making
de-caffeinated coffee. Caffeine is added to soft drinks and medicines as a stimulant and
diuretic. Roasted and ground coffee is a constituent of traditional medicines in
South-East Asia to alleviate stomach ache and diarrhoea, to increase blood
pressure, and as a diuretic. In some countries coffee leaves are used to make a hot
drink, like tea.
Coffee wood, from the main trunk, is used locally in construction. David
Livingstone, the nineteenth century explorer and missionary, reported seeing coffee trees being used to make huts in his travels in southern
Africa. The timber is straight, dense, strong and partially resistant to
termites. The wood is also used for furniture and as fuel wood.