Kola nut
Kola nut (Cola) is a genus of about 125 species of trees native to the tropical rainforests of Africa, classified in the family Malvaceae, subfamily Sterculioideae (or treated in the separate family Sterculiaceae). It is related to the South American genus Theobroma (Cacao). They are evergreen trees, growing to 20 m tall, with glossy ovoid leaves up to 30 cm long.

# Uses
The kola nut has a bitter flavor and caffeine content, and is chewed in many West African cultures, individually or in a group setting. It is often used ceremonially, presented to tribal chiefs or presented to guests. Chewing kola nut can ease hunger pangs. Frequent chewing of the kola nut can also lead to stained teeth. Among the urban youth of West Africa, kola nut is becoming less popular.
Kola was originally used to make cola soft drinks, though today most of these mass-produced beverages use artificial flavourings. Some exceptions are Barr's Red Kola, Harboe Original Taste Cola, Foxon Park Kola, Blue Sky Organic Cola, Sprecher's Puma Kola, and Cricket Cola, the latter being made from kola nuts and green tea.  In 2007, United Kingdom supermarket Tesco introduced an American Premium Cola that uses kola nuts, spices and vanilla. The emerging energy drink mix, Blow, contains 50mg of kola nut extract per vial (in addition to 240mg of caffeine per serving).
Outside of Africa, some species are cultivated for their nuts in Indonesia, Brazil, Jamaica and elsewhere in the humid tropics.
Kola nuts are often used to treat whooping cough and asthma.  The caffeine present acts as a bronchodilator, expanding the bronchial air passages.

# Pharmacological Effects
Kola nuts are used mainly for their stimulant and euphoriant qualities.  They have effects similar to other xanthine containing herbs like cocoa, tea, coffee, guarana and yerba mate.  However, the effects are distinctively different, producing a stronger state of euphoria and well being.  They have stimulant effects on the central nervous system and heart. Animal experiments indicate that kola nuts have analeptic and lipolytic (fat-burning) properties, and stimulate the secretion of gastric juices. Human studies show kola nuts have positive chronotropic and weak diuretic effects.  In humans it enhances alertness and physical energy, elevates mood, increases tactile sensitivity, suppresses the appetite and is used in Africa as an aphrodisiac.  Autonomic changes include increased body temperature, increased blood pressure and increased respiratory rate. Effects may last up to 6 hours after ingestion.

# Chemical Composition
- caffeine (2- 3.5 %)
- theobromine (1.0-2.5%)
- theophylline
- catechine
- epicatechine
- D-catechine
- phenolics
- phlobaphens
- Kola red
- betaine
- protein
- starch
- fat
- thiamine
- riboflavin
- niacin
- ascorbic acid
- betaine
- sugar
- gum
- cellulose
- water
- calcium
- potassium
- iron
- beta-carotene
- tannic acid

# Safety issues
Kola nuts contain high amounts of N-nitroso compounds which are carcinogenic. In Nigeria, where the chewing of Kola nuts is a common practice, there is a high incidence of oral and gastrointestinal cancer which may be related to this habit.

# History
The use of the kola nut, like the coffee berry and tea leaf, appears to have ancient origins. It is chewed in many West African cultures, individually or in a social setting, to restore vitality and ease hunger pangs. In 1911, kola became the focus of one of the earliest documented health scares when the US government seized 40 barrels and 20 kegs of Coca-Cola syrup in Chattanooga, Tennessee, alleging that the caffeine in its drink was "injurious to health". On March 13, 1911, the government initiated the United States v. Forty Barrels and Twenty Kegs of Coca-Cola, hoping to force Coca-Cola to remove caffeine from its formula by making exaggerated claims, such as that the excessive use of Coca-Cola at one girls' school led to "wild nocturnal freaks, violations of college rules and female proprieties, and even immoralities." Although the judge ruled in favor of Coca-Cola, two bills were introduced to the U.S. House of Representatives in 1912 to amend the Pure Food and Drug Act, adding caffeine to the list of "habit-forming" and "deleterious" substances which must be listed on a product's label.

# Literary References
Ceremonial sharing of the kola nut plays an important role in Chinua Achebe's 1959 novel Things Fall Apart.
In the movie "Tears of the Sun", the refugees give the SEALs a drink with Kola Nut to help them stay awake.
In Dorothy Dunnett's "House of Niccolo" series, Nicholas de Fluery samples the kola nut often in his adventures in Africa.