Breonadia
Breonadia is a monotypic genus of flowering plants in the family Rubiaceae. It was described by in 1975. The genus contains only one species, viz. "Breonadia salicina", which is found in tropical and southern Africa from Mali and Benin east to Ethiopia, south to South Africa, as well as Yemen, Saudi Arabia and Madagascar. "Breonadia salicina" (Matumi, , , , ) is a protected tree in South Africa. Characteristics. "Breonadia salicina" is a medium to large evergreen tree. The leaves occur alternately or in whorls of 3 to 5. The leaf shape is generally lanceolate and the leaf margin is entire. They are  leathery to the touch and usually a dark green with yellow on the midrib, which is slightly raised. The fruit is a capsule and they cluster in small spheres. The trees are monoecious with flowers that are small and yellow in color. The tree is generally found in subtropical to tropical climates, mainly in small populations in South Africa to Saudi Arabia and even Madagascar. It can be found in areas up to 2000 meters above sea level. They usually live on river banks or in the waters of a stream. Genetic Diversity. In a population of Breonadia salicina in  Saudi Arabia, genetic diversity was low within individuals of a single population, but was high between individuals from other populations. This means that the individual small populations of Breonadia salicina are very different from one another, but there is very little genetic diversity inside of the small populations. The populations are fairly far apart (the species is endangered) which would account for the high diversity rate between populations. The populations are also small in size and would be noticeably affected by genetic drift. Tropical trees also must deal with environmental factors such as deforestation and logging. "B. salicina" has been  used as a source of wood used to build houses and objects. Physical characteristics, such as diameter and density of xylem vessels, is due to the plant’s genetic makeup, but also many environmental factors as well (for this experiment it was rainfall). Medicinal Uses. "Breonadia salicina" is used in traditional African medicine. Mainly people use the bark to fight diarrhea and other stomach/digestive tract problems but also use other parts of the plant for different uses. The bark of "B. salicina" has been found to be rich in tannins. Tannins are polyphenols that have been found to help  with reducing growth of "E. coli" in digestive tracts. Leaf extracts of "B. salicina" have also been found to reduce activity of both gram-negative and gram-positive bacteria. It is believed that these same anti-bacterial properties of "B. salicina" can be used for the preservation of foods. Possible antifungal compounds have also been isolated in "B. salicina". The same antifungal compounds in "B. salicina" have been found to show activity in protecting oranges from infections.