Tetraclinis

Superregnum: Eukaryota
Regnum: Plantae
Divisio: Tracheophyta
Divisio: Pinophyta
Classis: Pinopsida
Ordo: Pinales

Familia: Cupressaceae
Subfamilia: Cupressoideae
Genus: Tetraclinis

Species: T. articulata

Paleospecies: †T. potlachensis – †T. salicornioides
Name

Tetraclinis Mast. J. Roy. Hort. Soc. London 14: 250 (1892)
References

Masters, W.T. 1892. Journal of the Royal Horticultural Society 14: 250.
Govaerts, R. et al. 2017. Tetraclinis in World Checklist of Selected Plant Families. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2017 Feb. 25. Reference page.
International Plant Names Index. 2017. Tetraclinis. Published online. Accessed: Feb. 25 2017.
Tropicos.org 2017. Tetraclinis. Missouri Botanical Garden. Published online. Accessed: 25 Feb. 2017.
Meyer, H.W. & Manchester, S.R. 1997. The Oligocene Bridge Creek flora of the John Day Formation, Oregon. University of California Publications in the Geological Sciences 141: 1–364. ISBN 978-0-520-09816-9. Reference page.

Tetraclinis (also called arar,[2] araar[3] or Sictus tree) is a genus of evergreen coniferous trees in the cypress family Cupressaceae, containing only one species, Tetraclinis articulata, also known as Thuja articulata,[4] sandarac, sandarac tree[5] or Barbary thuja,[6] endemic to the western Mediterranean region. It is native to northwestern Africa in the Atlas Mountains of Morocco, Algeria, and Tunisia, with two small outlying populations on Malta, and near Cartagena in southeast Spain. It grows at relatively low altitudes in a hot, dry subtropical Mediterranean climate.[7]

Its closest relatives are Platycladus, Microbiota, and Calocedrus, with the closest resemblance to the latter. In older texts, it was sometimes treated in Thuja or Callitris, but it is less closely related to those genera.[7]
Tetraclinis cones at Al Hoceima National Park

It is a small, slow-growing tree, to 6–15 m (rarely 20 m) tall and 0.5 m (rarely 1 m) trunk diameter, often with two or more trunks from the base. The foliage forms in open sprays with scale-like leaves 1–8 mm long and 1–1.5 mm broad; the leaves are arranged in opposite decussate pairs, with the successive pairs closely then distantly spaced, so forming apparent whorls of four. The cones are 10–15 mm long, green ripening brown in about 8 months from pollination, and have four thick scales arranged in two opposite pairs. The seeds are 5–7 mm long and 2 mm broad, with a 3–4 mm broad papery wing on each side.[7][8]

It is one of only a small number of conifers able to coppice (regrow by sprouting from stumps), an adaptation to survive wildfire and moderate levels of browsing by animals. Old trees that have sprouted repeatedly over a long period form large burls at the base, known as lupias.[7]

Uses and symbolism

It is the national tree of Malta, where it is known as għargħar (derived from the Arabic عَرْعَر ʿarʿar). It is now being used locally in afforestation projects.

The resin, known as sandarac, is used to make varnish and lacquer; it is particularly valued for preserving paintings.

The wood, known as thuya wood,[9] citron wood,[4] and alerce,[10] and historically also known as thyine wood, is used for decorative woodwork, particularly wood from burls at the base of the trunk. The market in Morocco is unsustainable, focusing as it does on the burl, and has resulted in mass deforestation of the species. The species is also threatened by overgrazing, which can kill the coppice regrowth before it gets tall enough to be out of the reach of livestock.[7]
Cultivation

The species is cultivated to be grown as an ornamental tree, valued in hot, dry climates. It is also pruned in a hedge form, for privacy and security.[8] The plant can be trained for use as bonsai specimens.
Fossil record

†Tetraclinis salicornioides leaf and cone fossils of Messinian age (ca. 5.7 Ma) have been uncovered in Monte Tondo and Borgo Tossignano, northern Apennines, Italy.[11]
Immature cones.jpg
Gallery

Tetraclinis articulata in the mountains of Cartagena, Spain

A cup made of root burl wood from the Essaouira area of Morocco

Illustration from Koehler's Medicinal-Plants (1887)

Tetraclinis articulata - Muséum de Toulouse

References

Sánchez Gómez, P.; Stevens, D.; Fennane, M.; Gardner, M.; Thomas, P. (2011). "Tetraclinis articulata". IUCN Red List of Threatened Species. 2011: e.T30318A9534227. doi:10.2305/IUCN.UK.2011-2.RLTS.T30318A9534227.en. Retrieved 19 November 2021.
"Tetraclinis articulata". The Gymnosperm Database. Retrieved 2011-02-13.
but it is ambiguous Arabic name also given to Juniperus phoenicea
Memidex: sandarac (wood) Retrieved 2012-05-16
Collins: sandarac and sandarac tree Retrieved 2012-05-16
Jacques Blondel & James Aronson: Biology and Wildlife of the Mediterranean Region, Oxford University Press 1999 Retrieved 2012-05-16
Farjon, A. (2005). Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew. ISBN 1-84246-068-4
Rushforth, K. (1999). Trees of Britain and Europe. Collins ISBN 0-00-220013-9.
Arc-genesis: Thuya Wood Archived 2011-08-08 at the Wayback Machine Retrieved 2012-05-16
"Definition of ALERCE".
Palaeoenvironmental analysis of the Messinian macrofossil floras of Tossignano and Monte Tondo (Vena del Gesso Basin, Romagna Apennines, northern Italy) - Vasilis Teodoridis, Zlatko Kvacek, Marco Sami and Edoardo Martinetto - December 2015 DOI: 10.14446/AMNP.2015.249.