Coffee is the name give to several species of plant in the genus Coffea (family Rubiaceae), including C. arabica and C. canephora which are cultivated for their beans (seeds) that are used to make the stimulatory drink. Coffee plants are small evergreen trees or shrubs often with multiple stems and smooth leaves. The leaves are oval in shape and dark, glossy green. Coffee plants produce clusters of cream-white flowers and a fruit, commonly referred to as a berry, which normally possesses two seeds. The fruit is green to begin with but ripens to a crimson red and turns black when dry. C. canephora can reach a height of 15 m (49 ft), but C. arabica is smaller, reaching only 4–5 m (13–16 ft). The trees can live for 20–30 years. Coffee may also be referred to as Arabian coffee (C. arabica) or robusta coffee (C.cenephora) and originates from Africa.