Duprez cypress : The world's only coniferous species

Tassili cypress, also known as Duprez cypress (Maurice DUPREZ, French soldier) or locally "tarout" in Tamacheq (Tuareg language), is a tree in the Cupressaceae family, native to the Sahara. The tree is endemic to the Tassili n'Ajjer mountain range in the central Sahara, more specifically in southeastern Algeria. It is a unique and isolated species. In 2001, there were only 233 specimens of this highly endangered species, the largest being over 20 metres high and 12 m in circumference. Some specimens are estimated to be over 2,000 years old, comparable to the extinction of the white rhinoceros. Total rainfall in this region is around 30 mm per year. This species differs from Cupressus sempervirens (the common Cypress) in the color of its foliage, which is bluer, with a white spot of resin on each leaf, and the shorter branches, often flattened in a single plane. Probably as a result of its isolation and low numbers, Tassili cypress has evolved a unique male apomixis reproductive system in which the seed develops entirely from the genetic content of the pollen. There is no genetic input from the female “parent”, who provides only nutrients. Tassili cypress is sometimes grown in western and southern Europe, partly for ex situ genetic conservation purposes, but also as an ornamental tree. Thousand-year-old trees in the desert The Duprez cypress (Cupressus dupreziana) is a true botanical curiosity, found only in the Tassili n'Ajjer (Algerian Sahara), on the Tamrit site (Tassili n'Ajjer plateau) at altitudes of between 1000 and 2000m. The extreme rarity of this species explains why, since 1978, it has been listed as one of the 12 most endangered species in the world. The Duprez cypress is one of the last survivors of a more humid period in the Tassili. The Mediterranean flora, which had spread as far south as the Sahara, then disappeared, except in certain mountain ranges, notably the Hoggar and Ajjers, where ecological conditions were a little more favorable.

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