Dr. John Robertson from the University of Leeds has drawn our attention to a disturbing note in a recent issue of the ‘New Scientist’. It appears that the African Violet is threatened with extinction in the wild.
World trade in the African Violet (Saintpaulia ionantha) is worth an estimated 30 million dollars per year. But all the plants are propagated in greenhouses. In the wild the species is on a list of 12 most threatened plants drawn up by the International Union for the Conservation of Nature and Natural Resources (IUCN).
Eighteen of the twenty known species are found only in Tanzania, and these in the Usambara mountains.
Though occupying only 2% of the country, the mountains contain an unrivalled diversity of animal and plant life. After the end of the most recent ice age, which brought lush forest to much of East Africa, the mountains became the only areas moist enough for the forest species to survive. The highlands each contain as many species as all the tropical forests of West Africa… So far, only Saintpaulia ionantha has been exploited by horticulturalists…
In 1983, Jon Lovett, a botanist working for the World Wildlife Fund, found what he thought was a new species in the largely undisturbed Uzungwa mountains. Careful identification has now proved it to be S. ionantha. A new locality for the species brought new hopes for its survival, but those hopes may be short lived. The Government-owned Tanzanian Wood Industries Corporation is receiving Finnish aid to build sawmills in the area. It intends to fell a third of the forest, 12,000 hectares in all.
The first sawmill in East Usambara is already in operation. In the less disturbed Uzungwa Mountains there is a scheme to clear 40,000 hectares for a sawmill under construction at Mangula…
Other plants growing wild in the woods that have won favour as houseplants in Europe and the US include the African Primrose, Streptocarpus, and the Busy Lizzy, Impatiens. Fifty three of the world’s 109 species of Busy Lizzy are found in the Tanzanian forests. Only nine species have so far been used by plant breeders.
Altogether a quarter of all plant species in Tanzania’s moist forests are unique to the Eastern arc mountains. They include timber species such as Cephaloshaera usambarensis, a relative of the nutmeg. It is fast growing and could become an important tree for timber plantations. The forests also contain 16 wild species of coffee, one of Tanzania’s principal exports. Ten are found only in Tanzania. Only three species are so far used commercially.