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Leyland cyprus

Author: Hon A/Prof Marius Rademaker, Dermatologist, Hamilton, New Zealand, 1999

Common name: Cyprus
Botanical name: Cupressocyparis leylandii
Family: Cupressaceae
Origin: Temperate regions; Eastern Mediterranean. A nice description of the site of origin of Cupressus was provided by the Roman philosopher Plinius: "cypress trees sprout spontaneously on Mt. Ida on the island of Crete, whenever the soil there is disturbed". Leyland cypress (X Cupressocyparis leylandii) is an intergeneric (of two separate genera) cross between Monterey cypress (Cupressus macrocarpa) and Alaska Cedar (Chamaecyparis nootkatensis) that originated in England in 1888.
Description: A fast growing (1 metre/year) evergreen tree. Reaches 20-30 m in height. When young, the bark is reddish brown and scaly, later developing gray weathered strips. The foliage is fine, scale-like and is arranged in decussate pairs which are green to bluish-green in colour. The fruit is a brown, round, small cone, 1-2 cm diameter. The flowers are monoecious; males are small reddish brown terminal cones; females are sightly larger, round, yellow green.
Uses: It is planted on a large scale as an ornamental plant, as a windbreak and as a forest tree. Becoming popular as a Christmas Tree.
Allergens: Carvacrol, terpenes, sesquiterpenes and possibly daucadienes or acoradienes.
Allergy: Contact dermatitis to the bark has been recorded, possibly as a cross reaction to colophony. It is increasing becoming a major cause of asthma and rhinoconjunctivitis, particularly in the Mediterannean.
Cross reactions: Colophony
Patch test: colophony, sesquiterpenes, saw dust, ether extract of leaf.



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