While there is much discussion about the origin of coffee, most experts agree that the birthplace of coffee was in Africa.  There are two types of coffee tree in use today.

• Coffea Arabica  from Ethiopia, known from prehistoric times.
• Coffea Robusta  from Congo, discovered in 1898.

The first coffee tree of economic importance was Coffee Arabica.  Arabica continues to be almost the sole choice for fine coffee production. The leaves of the coffee are 10-15 cm long ellipsoids, lustrous dark green with lighter underside. The flowers emerge from the branches together with the leaves.

Robusta coffee is more robust (resilient) than the Arabica trees, but produces an inferior tasting beverage with higher caffeine content.  Most grocery store style can coffee is produced from the Robusta tree. 

The white coffee flower has five petals and a scent resembling that of jasmine. The flowers last only 2-3 days. The coffee berries are cherry-sized and green at first, turning dark red later on. The ripening takes eight months. The coffee tree starts flowering at 2-4 years old and it can simultaneously have flowers and berries in all stages of development.  The coffee tree can grow to heights of 10 meters if not pruned, but producing countries will maintain the coffee at a height reasonable for easy harvesting.

The coffee tree requires a mean temperature of 66-77 degrees Fahrenheit. Thus, the coffee tree is a tropical plant. The coffee plant cannot stand frost but does not die from an occasional cold night. It needs lots of water, requiring annual rainfall of 59 inches. Coffee plantations are normally situated in the altitude range of 984-6562 feet around the Equator.  The best Arabica coffees are generally grown at altitudes greater than 3500 feet, with notable exceptions such as Hawaiian Kona.

A coffee tree can be harvested from the 5th year and harvesting can occur many times throughout the year. At 25 the tree becomes old but it may live to be a wiry centenarian.