Cupressus dupreziana A. Camus
C. lereddei Gaussen. C. sempervirens var. dupreziana (A. Camus) Silba.
Eng.: Saharian cypress. Spa.: Ciprés del Sahara. Fre.: Cyprès de Duprez, cyprès du Tassili. Tamahaq: Tarut.
Evergreen tree, monoecious, about 20 m in height, irregular in shape but ± ovoid-rounded. Trunk tortuous up to 4 m in diameter. Very different in general appearance from C. sempervirens -according to some authors C. dupreziana is closer to C. funebris Endl. from China-. Bark red-brown on branches and in juveniles, turning darker and greyish with age. Branchlets covered with squamiform, oval (1-1.5 mm) leaves, dull green in colour. Male cones elliptical (3-4 mm) born solitary at end of the branchlets. Female cones or strobili ovoid or ellipsoid (12-24 × 10-17 mm), light brown in colour, with 10-12 peltate scales with a shield that is wider than long, with a very short, blunt central mucro. Seeds ± flattened, with a wide wing.
Flowering:
Usually in spring, though it ultimately depends on rainfall.
Fruiting:
Fruiting and seed dissemination is very conditional upon rainfall, even in greater extent than flowering.
Habitat:
Dry riverbeds and riverbanks of desert mountains, between 1430 and 1830 m altitude.
Distribution:
Endemic of the central Sahara: massifs of Tassili-n-Ajjer (SW part of the plateau, in the Meddak region, Tamrit valley, and Tassili Hedjiri and Amiok regions) and Ahaggar (Algeria) (in the Ahaggar only some dead trees remain, still standing).
Observations:
The current status of this cypress is quite critical. All authors agree that this is a species in danger of extinction, since natural regeneration has been practically non-existent for decades. Of the approximately 230 surviving individuals, only a few produce and mature seeds, very sporadically, which don’t thrive in a soil where moisture and organic matter are practically null. This tree covered much of North Africa during the Tertiary. In the early Quaternary, it still survived in an extensive area that would run from the Saharan Atlas to the Sahel, as shown by several palynological studies in Algeria, Tunisia, Niger and Chad. There is an extraordinary chorological and paleoclimatic interest in this living fossil. Some ancient specimens were born when the Sahara had a savannah look, even with forests, mainly following the course of rivers, in a cooler and wetter climate than today. The carbon-14 dating of a series of specimens performed by Abdoun et al. (2005), show specimens up to 2,400 years old. A program of artificial regeneration of the species in its natural habitat should be undertaken.
Conservation status:
In the IUCN Red List of Threatened Species it is listed at a global level as Endangered (EN) (Abdoun et al. 2013). These authors group this species with C. atlantica into one species separated into two varieties, calling the central Saharan cypresses as C. dupreziana var. dupreziana, which they list as Critically Endangered (CR). In Algeria it is included in the List of protected non cultivated flora (Executive Decree 12-03 on 4-Jan-2012).