|Range of Cupressus dupreziana|
Cupressus dupreziana, the Saharan Cypress or tarout, is a very rare coniferous tree native to the Tassili n'Ajjer mountains in the central Sahara Desert, southeast Algeria, where it forms a unique population of trees hundreds of kilometres from any other trees. There are only 233 specimens of this critically endangered species, the largest about 22 m tall. The majority are very old, estimated to be over 2000 years old, with very little regeneration due to the increasing desertification of the Sahara. Rainfall totals in the area are estimated to be about 30 mm annually. The largest one is named Tin-Balalan is believed to be the oldest tarout trees with a circumference of 12 meters or 36 feet.
This species is distinct from the allied Cupressus sempervirens (Mediterranean Cypress) in its much bluer foliage with a white resin spot on each leaf, the smaller shoots often being flattened in a single plane. It also has smaller cones, only 1.5-2.5 cm long. Cupressus atlantica (Moroccan Cypress) is more similar, and is treated as a variety of the Saharan Cypress (C. dupreziana var. atlantica) by some authors.
Probably as a result of its isolation and low population, the Saharan Cypress has evolved a unique reproductive system of male apomixis whereby the seeds develop entirely from the genetic content of the pollen. There is no genetic input from the female "parent", which only provides nutritional sustenance (Pichot et al., 2000). The Moroccan Cypress does not share this characteristic.
An International Arboretum is being established in Canberra, Australian Capital Territory (ACT), Australia within which will be established forests of rare and endangered species from throughout the world. One of these forests is dedicated to Cupressus dupreziana and 1300 of the trees have been propagated for planting in late 2007.
- Conifer Specialist Group (1998). Cupressus dupreziana var. dupreziana. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 10 June 2006. Listed as Critical (CR A2c, C1 v2.3)
- Stewart, P.J. 1969. Cupressus dupreziana, threatened conifer of the Sahara. Biological Conservation 2: 10-12.
- Pichot, C., Fady, B., & Hochu, I. 2000. Lack of mother tree alleles in zymograms of Cupressus dupreziana A. Camus embryos. Ann. For. Sci. 57: 17–22. Full article (pdf file)
- Pichot, C., El Maátaoui, M., Raddi, S. & Raddi, P. 2001. Surrogate mother for endangered Cupressus. Nature 412: 39.
- Zsolt Debreczy, Istvan Racz (2012). Kathy Musial, ed. Conifers Around the World (1st ed.). DendroPress. p. 1089. ISBN 9632190610.
- Abdoun, F., Gardner, M. & Griffiths, A. 2013. Cupressus dupreziana. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 11 November 2013.
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