Coffea

Coffea
Flowering branches of Coffea arabica
Scientific classification
Kingdom:	Plantae
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Gentianales
Family:	Rubiaceae
Tribe:	Coffeeae
Genus:	Coffea L.
Type species
Coffea arabica L.

Coffea canephora

Coffea is a genus of flowering plants whose seeds, called coffee beans, are used to make various coffee beverages and products. 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 Africa.

Cultivation and use

Coffea cherries, Bali

There are over 120 species of Coffea, which is grown from seed. The two most popular are Coffea arabica (commonly known simply as "Arabica") accounts for 75–80 percent of the world's coffee production, while Coffea canephora (known as "Robusta") accounts for about 20 percent.^[1]

The trees produce edible red or purple fruits called "cherries" that are described either as epigynous berries or as indehiscent drupes.^[2] These contain two seeds, called "coffee beans", though they are not true beans. In about 5-10% of any crop of coffee cherries, only a single bean is found. Called a peaberry, it is smaller and rounder than a normal coffee bean. These are often removed from the yield and either sold separately or discarded.

When grown in the tropics, coffee is a vigorous bush or small tree that usually grows to a height of 3–3.5 m (9.8–11.5 ft). Most commonly cultivated coffee species grow best at high elevations, but do not tolerate freezing temperatures.

The tree of Coffea arabica will grow fruits after three to five years, producing for an average of 50 to 60 years, although up to 100 is possible.^[3] The white flowers are highly scented. The fruit takes about 9 months to ripen.

Coffea flower

Coffea cherry cross section

Coffea racemosa fruits

Ecology

The caffeine in coffee "beans" serves as a toxic substance protecting the seeds of the plant, a form of natural plant defense against herbivory. Fruits and leaves also contain caffeine, and can be used to make a tea. The fruit is also used in many brands of soft drink as well as pre-packaged teas.

Several insect pests affect coffee production, including the coffee borer beetle (Hypothenemus hampei) and the coffee leafminer (Leucoptera caffeina).

Coffee is used as a food plant by the larvae of some Lepidoptera (butterfly and moth) species, Dalcera abrasa, turnip moth and some members of the genus Endoclita, including E. damor and E. malabaricus.

Research

New species of Coffea are still being identified in the 2000s. In 2008 and 2009, researchers from the Royal Botanic Gardens, Kew named seven from the mountains of northern Madagascar, including C. ambongensis, C. boinensis, C. labatii, C. pterocarpa, C. bissetiae, and C. namorokensis.^[4]

In 2008, two new species were discovered in Cameroon. Coffea charrieriana, which is caffeine-free, and Coffea anthonyi.^[5] By crossing the new species with other known coffees, two new features might be introduced to cultivated coffee plants: beans without caffeine and self-pollination.

In 2014, the coffee genome was published, with more than 25,000 genes identified. This revealed that coffee plants make caffeine using a different set of genes from those found in tea, cacao and other such plants.^[6]

Species

References

External links

Wikimedia Commons has media related to Coffea.

Wikispecies has information related to Coffea

• World Checklist of Rubiaceae
• Coffee & Conservation