Cupressus dupreziana, the Saharan Cypress, 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 231 specimens of this critically endangered species, the largest about 20 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. Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms (as opposed to folk taxonomy). ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern... Orders & Families Cordaitales† Pinales   Pinaceae- Pine family   Araucariaceae- Araucaria family   Podocarpaceae- Yellow-wood family   Sciadopityaceae- Umbrella-pine family   Cupressaceae- Cypress family   Cephalotaxaceae- Plum-yew family   Taxaceae- Yew family Vojnovskyales† Voltziales† The conifers, division Pinophyta, are one of 13 or 14 division level taxa within the Kingdom Plantae. ... Orders & Families Cordaitales† Pinales   Pinaceae- Pine family   Araucariaceae- Araucaria family   Podocarpaceae- Yellow-wood family   Sciadopityaceae- Umbrella-pine family   Cupressaceae- Cypress family   Cephalotaxaceae- Plum-yew family   Taxaceae- Yew family Vojnovskyales† Voltziales† The conifers, division Pinophyta, are one of 13 or 14 division level taxa within the Kingdom Plantae. ... Families Pinaceae, pine family Araucariaceae, araucaria family Podocarpaceae, yellow-wood family Phyllocladaceae Sciadopityaceae, umbrella-pine family Cupressaceae, cypress family Cephalotaxaceae, plum-yew family Taxaceae, yew family The Order Pinales in the Division Pinophyta, Class Pinopsida comprises all the extant conifers. ... Genera Actinostrobus Athrotaxis Austrocedrus Callitris - Cypress-pine Callitropsis - Cypress * (Cupressus) Calocedrus - Incense-cedar Chamaecyparis - Cypress Cryptomeria - Sugi Cunninghamia - Cunninghamia Cupressus - Cypress Diselma - Diselma Fitzroya - Alerce Fokienia - Fujian Cypress Glyptostrobus - Chinese Swamp Cypress Juniperus - Juniper Libocedrus Metasequoia - Dawn Redwood Microbiota - Microbiota Neocallitropsis Papuacedrus * (Libocedrus) Pilgerodendron * (Libocedrus) Platycladus - Chinese Arborvitae Sequoia - Coast... Species See text. ... In biology, binomial nomenclature is the formal method of naming species. ... Orders & Families Cordaitales† Pinales   Pinaceae- Pine family   Araucariaceae- Araucaria family   Podocarpaceae- Yellow-wood family   Sciadopityaceae- Umbrella-pine family   Cupressaceae- Cypress family   Cephalotaxaceae- Plum-yew family   Taxaceae- Yew family Vojnovskyales† Voltziales† The conifers, division Pinophyta, are one of 13 or 14 division level taxa within the Kingdom Plantae. ... For other uses, see Tree (disambiguation). ... Landsat image of the Tassili nAjjer The Tassili nAjjer is a mountain range in the Sahara desert in southeast Algeria. ... The Sahara is the worlds second largest desert (second to Antarctica), over 9,000,000 km² (3,500,000 mi²), located in northern Africa and is 2. ... The endangered Sea Otter An endangered species is a population of organisms (frequently but not always a taxonomic species) which is either (a) so few in number or (b) threatened by changing environmental or predation parameters that it is at risk of becoming extinct. ... Ship stranded by the retreat of the Aral Sea Desertification is the degradation of land in arid, semi arid and dry sub-humid areas resulting from various factors including climatic variations and human activities. ...

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. Binomial name Cupressus sempervirens L. Cupressus sempervirens, the Mediterranean Cypress, is a species of cypress native to the eastern Mediterranean region, in northeast Libya, southeast Greece (Crete, Rhodes), southern Turkey, Cyprus, western Syria, Lebanon and western Jordan, and also a disjunct population in Iran. ... In botany, a leaf is an above-ground plant organ specialized for photosynthesis. ... A cone (in formal botanical usage: strobilus, plural strobili) is an organ on plants in the division Pinophyta (conifers) that contains the reproductive structures. ... Binomial name Cupressus atlantica Gaussen Cupressus atlantica, the Moroccan Cypress, is a rare coniferous tree endemic to the valley of the Oued-n-Fis river in the High Atlas Mountains south of Marrakech in western Morocco. ...

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. A speculative phylogenetic tree of all living things, based on rRNA gene data, showing the separation of the three domains, bacteria, archaea and eukaryotes. ... In botany, apomixis is biological reproduction without fertilization, meiosis or production of gametes, with the result that the seeds are genetically identical to the parent plant. ... A ripe red jalapeno cut open to show the seeds For other uses, see Seed (disambiguation). ... SEM image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomea purpurea), hollyhock (Sildalcea malviflora), lily (Lilium auratum), primrose (Oenothera fruticosa), and castor bean (Ricinus communis). ...

The Saharan Cypress is occasionally cultivated in southern and western Europe, in part for ex situ genetic conservation, but also as an ornamental tree. Europe is conventionally considered one of the seven continents of Earth which, in this case, is more a cultural and political distinction than a physiographic one, leading to some dispute as to Europes actual borders. ... An ornamental is a plant variety that is grown for its beauty (in its end use), rather than commercial or other value. ...

References

• 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.

External links

• Gymnosperm Database: Cupressus dupreziana
• Arboretum de Villardebelle - photos of trees in the Sahara