Coffea charrieriana

Vegetative characteristics Coffea charrieriana is a tall shrub with wide branchlets. Through further analysis, it was found that instead of accumulation of caffeine, the deficient caffeine synthase gene responsible for caffeine production had instead produced a substance called theobromine in its place. This discovery by scientists led to further understanding about the genetics of caffeine in Coffea plants, and the ability to hybridize coffee plants with caffeine-free plants to produce a decaf line of seeds with lower caffeine concentrations. It also opened up the option of removing this particular gene in plants containing caffeine to create a caffeine-free plant. and 0.8% dry matter basis. C. charrieriana also has lower caffeoylquinic acids (CQA) than other Coffea species. From analysing the fatty acid content alone, C. charrieriana is most closely related to C. congensis and forms a separate clade from the other 59 Coffea genotypes. Coffea charrieriana also has the largest chloroplast genome within the Coffea genus. When clustering the 52 species from Coffea and Psilanthus, C. charrieriana, along with another species, P. travancorensis, were excluded from the clusters due to poor analysis results. Though C. charrieriana originates from Cameroon, genetic results suggest a placement of C. charrieriana between the two genera of Psilanthus and Coffea. It is genetically similar to West and Central African Coffea species but shares morphological similarities with Psilanthus, such as its vegetation. The difficulty in grouping C. charrieriana is likely the result of ancient hybridisation between C. charrieriana and a Psilanthus chloroplast, leading to a mixed genome. Alkaloids are found in many plants including coffee and tea, but only very small amounts are present in C. charrieriana. ==Taxonomy==

It was described by Piet Stoffelen and François Anthony in 2008. The type specimen was collected in Cameroon in the Bakossi Forest Reserve, 2km east of a bridge on the Mungo River. ==Distribution and habitat==

This plant is endemic to West Cameroon in the Bakossi Forest Reserve. It grows in a habitat of wet rainforest on rocky slopes of an altitude of 160 m and a mean elevation range of 300 m. It is highly threatened by deforestation for logging and palm oil production in its vulnerable lowland forest habitat. ==Conservation==

Coffea charrieriana is a critically endangered species and is only known from one location. ==History==

Coffea charrieriana was discovered in 2008 and the findings were published in a paper named "A new caffeine-free coffee from Cameroon" to the Botanical Journal of the Linnean Society. Though C. charrieriana was identified as morphologically different to previously identified Coffea species, further work was not done until 1997. In 1997 the cuttings were sent to the Institute of Research for Development (IRD) in which further study such as observations of the seed coat, anatomical observations of the leaves and biochemical analysis was undertaken. It was not until 2008, after morphological and genetic studies of this species, that it was recognised as a new species of Coffea. Genotyping analysis reveals C. charrieriana to have diverged from a common ancestor 11.15 million years ago. ==Cultivation and use==

Coffea charrieriana grows in wet places with plenty of sunshine. During dry periods, the species undergoes floral bud morphogenesis, but the flowering buds do not emerge until the next rainfall event. After rain, a flowering event is seen in seven days. The time it takes for flowering of all Coffea species ranges from 5–13 days, making correct timing of hybridization difficult. Similar to other Coffea species, the fleshy fruit of C. charrieriana contains edible beans. These can be prepared by drying, roasting or grinding, generally to make coffee. As a naturally occurring caffeine-free coffee, it provides an alternative over artificially decaffeinated coffee. With increasing demand for decaffeinated coffee, methods such as plant hybridization between coffee-free species, biotechnology interference of genetics and chemical extraction have been used to artificially decrease caffeine content. Generally, the presence of caffeine acts on the tastebuds, giving caffeinated products a distinct flavour, so as a caffeine-free species, C. charrieriana may not be preferable to coffee drinkers who prefer the taste provided by caffeine. C. charrieriana can be used in plant hybridization as the theobromine can be transferable between breeds, allowing caffeine concentration to be altered when crossed with a species containing caffeine. ==References==