coffee plant

''Coffea'' is a genus of flowering plants in the family Rubiaceae. ''Coffea'' species are shrubs or small trees native to tropical and southern Africa and tropical Asia. The seeds of some species, called coffee beans, are used to flavor various beverages and products. The fruits, like the seeds, contain a large amount of caffeine, and have a distinct sweet taste and are often juiced. The plant 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

There are over 120 species of ''Coffea'', which is grown from seed. The two most popular are ''Coffea arabica'' (commonly known simply as "Arabica"), which accounts for 60–80% of the world's coffee production, and ''Coffea canephora'' (known as " Robusta"), which accounts for about 20–40%. '' C. arabica'' is preferred for its sweeter taste, while ''C. canephora'' has a higher caffeine content. ''C. arabica'' has its origins in the highlands of Ethiopia and the Boma Plateau of Sudan, and was the result of a hybrid between ''C. canephora'' and ''C. eugenioides''.

The trees produce edible red or purple fruits, which are described either as epigynous berries or as indehiscent drupes. The fruit is often referred to as a "coffee cherry," and it contains two seeds, called "coffee beans." Despite these terms, coffee is neither a true cherry (the fruit of certain species in the genus ''Prunus'') nor a true bean (seeds from plants in the family ''Fabaceae'').

In about 5–10% of any crop of coffee fruits, only a single bean is found. Called a peaberry, it is smaller and rounder than a normal coffee bean.

When grown in the tropics, coffee is a vigorous bush or small tree that usually grows to a height of . 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. The white flowers are highly scented. The fruit takes about nine months to ripen.

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. Caffeine simultaneously attracts pollinators, specifically honeybees, by creating an olfactory memory that signals bees to return to the plant's flowers. Not all ''Coffea'' species contain caffeine, and the earliest species had little or no caffeine content. Caffeine has evolved independently in multiple lineages of ''Coffea'' in Africa, perhaps in response to high pest predation in the humid environments of West-Central Africa. Caffeine has also evolved independently in the more distantly related genera ''Theobroma'' ( cacao) and ''Camellia'' (tea). This suggests that caffeine production is an adaptive trait in coffee and plant evolution. The fruit and leaves also contain caffeine, and can be used to make coffee cherry tea and coffee-leaf 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.''

In 2008, two new species were discovered in Cameroon. '' Coffea charrieriana'', which is caffeine-free, and '' Coffea anthonyi''. 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 2011, ''Coffea'' absorbed the twenty species of the former genus ''Psilanthus'' due to the morphological and genetic similarities between the two genera. Historically, the two have been considered distinct genera due to differences in the length of the corolla tube and the anther arrangement: ''Coffea'' with a short corolla tube and exserted style and anthers; ''Psilanthus'' with a long corolla tube and included anthers. However, these characteristics were not present in all species of either respective genus, making the two genera overwhelmingly similar in both morphology and genetic sequence. This transfer expanded ''Coffea'' from 104 species to 124, and extended its native distribution to tropical Asia and Australasia.

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.

In 2017, a robust and almost fully resolved phylogeny of the entire genus was published. In addition to resolving the relationships of ''Coffea'' species, this study's results suggest Africa or Asia as the likely ancestral origin of Coffea and point to several independent radiations across Africa, Asia, and the Western Indian Ocean Islands.

In 2020 a technique of DNA fingerprinting, or genetic authentication of plant material was proven effective for coffee. For the study, scientists used DNA extraction and SSR marker analysis. This technique or ones similar may allow for several improvements to coffee production such as improved information for farmers as to the susceptibility of their coffee plants to pests and disease, a professionalized coffee seed system, and transparency and traceability for buyers of green, un-roasted coffee.

Species

# '' Coffea abbayesii'' J.-F.Leroy
# '' Coffea affinis'' De Wild.
# '' Coffea alleizettii'' Dubard
# '' Coffea ambanjensis'' J.-F.Leroy
# '' Coffea ambongenis'' J.-F.Leroy ex A.P.Davis
# '' Coffea andrambovatensis'' J.-F.Leroy
# '' Coffea ankaranensis'' J.-F.Leroy ex A.P.Davis
# '' Coffea anthonyi'' Stoff. & F.Anthony
# ''Coffea arabica'' L.
# '' Coffea arenesiana'' J.-F.Leroy
# '' Coffea augagneurii'' Dubard
# '' Coffea bakossii'' Cheek & Bridson
# '' Coffea benghalensis'' B.Heyne ex Schult.
# '' Coffea bertrandii'' A.Chev.
# '' Coffea betamponensis'' Portères & J.-F.Leroy
# '' Coffea bissetiae'' A.P.Davis & Rakotonas.
# '' Coffea boinensis'' A.P.Davis & Rakotonas.
# '' Coffea boiviniana'' A.P.Davis & Rakotonas.
# '' Coffea bonnieri'' Dubard
# '' Coffea brassii'' ( J.-F.Leroy) A.P.Davis
# '' Coffea brevipes'' Hiern
# '' Coffea bridsoniae'' A.P.Davis & Mvungi
# '' Coffea buxifolia'' A.Chev.
# ''Coffea canephora'' (''"Coffea robusta"'') Pierre ex A.Froehner
# '' Coffea carrissoi'' A.Chev.
# '' Coffea charrieriana'' Stoff. & F.Anthony
# '' Coffea cochinchinensis'' Pierre ex Pit.
# '' Coffea commersoniana'' ( Baill.) A.Chev.
# '' Coffea congensis'' A.Froehner
# '' Coffea costatifructa'' Bridson
# '' Coffea coursiana'' J.-F.Leroy
# '' Coffea dactylifera'' Robbr. & Stoff.
# '' Coffea decaryana'' J.-F.Leroy
# '' Coffea dubardii'' Jum.
# '' Coffea ebracteolata'' ( Hiern) Brenan
# '' Coffea eugenioides'' S.Moore
# '' Coffea fadenii'' Bridson
# '' Coffea farafanganensis'' J.-F.Leroy
# '' Coffea floresiana'' Boerl.
# '' Coffea fotsoana'' Stoff. & Sonké
# '' Coffea fragilis'' J.-F.Leroy
# '' Coffea fragrans'' Wall. ex Hook.f.
# '' Coffea gallienii'' Dubard
# '' Coffea grevei'' Drake ex A.Chev.
# '' Coffea heimii'' J.-F.Leroy
# '' Coffea homollei'' J.-F.Leroy
# '' Coffea horsfieldiana'' Miq.
# '' Coffea humbertii'' J.-F.Leroy
# '' Coffea humblotiana'' Baill.
# '' Coffea humilis'' A.Chev.
# '' Coffea jumellei'' J.-F.Leroy
# '' Coffea kapakata'' ( A.Chev.) Bridson
# '' Coffea kianjavatensis'' J.-F.Leroy
# '' Coffea kihansiensis'' A.P.Davis & Mvungi
# '' Coffea kimbozensis'' Bridson
# '' Coffea kivuensis'' Lebrun
# '' Coffea labatii'' A.P.Davis & Rakotonas.
# '' Coffea lancifolia'' A.Chev.
# '' Coffea lebruniana'' Germ. & Kester
# '' Coffea leonimontana'' Stoff.
# '' Coffea leroyi'' A.P.Davis
# '' Coffea liaudii'' J.-F.Leroy ex A.P.Davis
# '' Coffea liberica'' Hiern
# '' Coffea ligustroides'' S.Moore
# '' Coffea littoralis'' A.P.Davis & Rakotonas.
# '' Coffea lulandoensis'' Bridson
# '' Coffea mabesae'' (Elmer) J.-F.Leroy
# '' Coffea macrocarpa'' A.Rich.
# '' Coffea madurensis'' Teijsm. & Binn. ex Koord.
# '' Coffea magnistipula'' Stoff. & Robbr.
# '' Coffea malabarica'' (Sivar., Biju & P.Mathew) A.P.Davis
# '' Coffea mangoroensis'' Portères
# '' Coffea mannii'' ( Hook.f.) A.P.Davis
# '' Coffea manombensis'' A.P.Davis
# '' Coffea mapiana'' Sonké, Nguembou & A.P.Davis
# '' Coffea mauritiana'' Lam.
# '' Coffea mayombensis'' A.Chev.
# '' Coffea mcphersonii'' A.P.Davis & Rakotonas.
# '' Coffea melanocarpa'' Welw. ex Hiern
# '' Coffea merguensis'' Ridl.
# '' Coffea millotii'' J.-F.Leroy
# '' Coffea minutiflora'' A.P.Davis & Rakotonas.
# '' Coffea mogenetii'' Dubard
# '' Coffea mongensis'' Bridson
# '' Coffea montekupensis'' Stoff.
# '' Coffea montis-sacri'' A.P.Davis
# '' Coffea moratii'' J.-F.Leroy ex A.P.Davis & Rakotonas.
# '' Coffea mufindiensis'' Hutch. ex Bridson
# '' Coffea myrtifolia'' ( A.Rich. ex DC.) J.-F.Leroy
# '' Coffea namorokensis'' A.P.Davis & Rakotonas.
# '' Coffea neobridsoniae'' A.P.Davis
# '' Coffea neoleroyi'' A.P.Davis
# '' Coffea perrieri'' Drake ex Jum. & H.Perrier
# '' Coffea pervilleana'' ( Baill.) Drake
# '' Coffea pocsii'' Bridson
# '' Coffea pseudozanguebariae'' Bridson
# '' Coffea pterocarpa'' A.P.Davis & Rakotonas.
# '' Coffea racemosa'' Lour.
# '' Coffea rakotonasoloi'' A.P.Davis
# '' Coffea ratsimamangae'' J.-F.Leroy ex A.P.Davis & Rakotonas.
# '' Coffea resinosa'' ( Hook.f.) Radlk.
# '' Coffea rhamnifolia'' ( Chiov.) Bridson
# '' Coffea richardii'' J.-F.Leroy
# '' Coffea sahafaryensis'' J.-F.Leroy
# '' Coffea sakarahae'' J.-F.Leroy
# '' Coffea salvatrix'' Swynn. & Philipson
# '' Coffea sambavensis'' J.-F.Leroy ex A.P.Davis & Rakotonas.
# '' Coffea sapinii'' ( De Wild.) A.P.Davis
# '' Coffea schliebenii'' Bridson
# '' Coffea semsei'' ( Bridson) A.P.Davis
# '' Coffea sessiliflora'' Bridson
# '' Coffea stenophylla'' G.Don
# '' Coffea tetragona'' Jum. & H.Perrier
# '' Coffea togoensis'' A.Chev.
# '' Coffea toshii'' A.P.Davis & Rakotonas.
# '' Coffea travancorensis'' Wight & Arn.
# '' Coffea tricalysioides'' J.-F.Leroy
# '' Coffea tsirananae'' J.-F.Leroy
# '' Coffea vatovavyensis'' J.-F.Leroy
# '' Coffea vavateninensis'' J.-F.Leroy
# '' Coffea vianneyi'' J.-F.Leroy
# '' Coffea vohemarensis'' A.P.Davis & Rakotonas.
# '' Coffea wightiana'' Wall. ex Wight & Arn.
# '' Coffea zanguebariae'' Lour.

References

External links

World Checklist of Rubiaceae

Coffee & Conservation

{{Authority control

Fruits originating in Africa
Medicinal plants of Asia
Medicinal plants of Africa
Rubiaceae genera
Crops
Herbal and fungal stimulants