(Cupressus macrocarpa × Chamaecyparis nootkatensis) Cupressaceae
- Evergreen conifer, to 60-70 ft (18-21 m) tall, 8-15 ft (2.5-4.5 m) wide, columnar to pyramidal form. Leaves scale-like, opposite leaf pairs alternating to form 4 longitudinal rows, individual leaves 1.5-3 mm long, green to bluish-green above and below, arranged in flat sprays on long slender branches. Although fruits rarely, cones are round and about 1.5-2.0 cm wide.
- Sun. Adaptable and fast growing; can be grown as a hedge (10-15 ft). Grown commercially as a Christmas tree in some areas.
- Hardy to USDA Zone 6 An intergeneric hybrid of Cupressus macrocarpa (Monterey Cypress) × Chamaecyparis nootkatensis (Alaska Cedar), which has occurred many times.
- Many cultivars have been selected, including:
- Castlewellan (syn.Castlewellan Gold) - vigorous grower, but slower than ×C. leylandii, dense crown, conical to columnar, summer foliage golden yellow in cool regions to greenish yellow in warm climates. Popular. Of seedling origin in 1962 at Castlewellan, North Ireland.
- Emerald Isle™ (syn. Moncal) - foliage bright green, in flat sprays, dense, a Monrovia introduction in 1992, originally from Britain.
- Golconda - yellow-gold foliage persists year round, compact pyramid form, fast growing, originally from Briton.
- Gold Nugget - bright golden yellow foliage, compact and erect form.
- Gold Rider - yellow-golden foliage, in winter yellow with green tips, open, considered one of the best "golden" cultivars. Originated as a branch sport in Holland in the 1980s.
- Naylor's Blue - foliage soft to deep blue-green, feather-like (plumose), considered one of the bluest selections, somewhat open form, youngest branches round in cross-section, rarely produces cones. Originated in Leighton Hall, Wales in 1911.
- Robinson's Gold - foliage varies from bright gold-yellow to lemon-green, fast growing. Found as a seedling by George Robinson in 1962 in Belfast, North Ireland.
- Silver Dust - foliage green with scattered cream-white splashes and streaks, sprays flat. Originated as a branch sport at the U.S. Arboretum, Washington, D.C.
- leylandii: after C.J. Leyland, a sea captain, who grew some of the first hybrids on his property in England in 1888.
- Oregon State Univ. campus:
- a hedge on the east side of the surplus property building at 644 SW 13th St., across from Independent Auto Werks.
- southeast corner Richardson, selection Emerald Isle™