The Coffee Plant Two primary species of coffee are grown and traded commercially: coffea arabica (arabica) and coffea canephora (robusta). Arabica accounts for 75-80% of the world’s production, with the top 10 percent graded as specialty beans. The robusta coffee plant is more resilient than the arabica shrubs. Robusta coffee has twice as much caffeine as arabica, and while it is seldomly used in specialty coffees because of its inferior taste, it is frequently used in instant coffees and popular commercial blends. Coffee grows in tropical and subtropical climates at altitudes ranging from sea level to 6,000 feet, predominately in Central America, South America, eastern Africa, and Indonesia. Coffee generally grows better at higher altitudes, producing coffee with a “hard bean”, a more flavorful coffee. However, some of the world’s favorite coffees are exceptions to this rule: Hawaiian Kona, Sumatra Lintong, and Jamaica Blue Mountain. The coffee plant is a woody perennial evergreen with broad, shiny leaves that are shaped like spearheads. The flowers of the coffee plant are small, white, star-shaped, and scented like jasmine. These flowers appear for three days, and six to nine months later the tree’s fruit, called cherries, begin to form. The cherries ripen from green to yellow to red. Ripe cherries have multiple layers: the outer red skin, a pulp, a membrane called parchment, another membrane called silver skin, and two coffee seeds (beans). Occasionally the fruit produces only one bean; this is called a peaberry. A coffee tree typically yields good crops for about 25 years. Arabica coffee is self-pollinating, while robusta coffee can cross-pollinate with other plants.