As a hybrid, although fertility of certain Leyland cypress forms were recently reported, most Leyland cypress were thought to be sterile, and nearly all the trees now
seen have resulted from cuttings originating from those few plants.
Eventually they found the six original trees developed by Leyland, and began propagating the species.
The two parent species would not likely cross in the wild, as their natural ranges are more than 400 miles (640 km) apart, but in 1888, the hybrid cross occurred when the
female flowers or cones of Nootka cypress were fertilised by pollen from Monterey cypress.
 In 1953, a freak tornado blew down one of the original trees at Haggerston (the other original five trees still survive), on which the research division of the Forestry
Commission started developing additional hybrids.
 Little (2006) proposed another alternative by transferring all the North American species of Cupressus, including the Monterey cypress (C. macrocarpa), to Callitropsis.
The shallow root structure also means that it is poorly adapted to areas with hot summers, such as the southern half of the United States.
The Leyland cypress, Cupressus × leylandii, often referred to simply as leylandii, is a fast-growing coniferous evergreen tree much used in horticulture, primarily for hedges
 Over 40 forms of Leyland cypress are known, and as well as ‘Haggerston Grey’ and ‘Leighton Green’, other well-known forms include ‘Stapehill’, which was discovered
in 1940 in a garden in Ferndown, Dorset by M. Barthelemy and ‘Castlewellan’, which originated from a single mutant tree in the Castlewellan estate arboretum in Northern Ireland.
However, their rapid growth (up to 1 m per year), their thick shade and their large potential size (often more than 20 m high in garden conditions, and they can reach at least
35 m) make them problematic.
 Naylor commissioned Edward Kemp to lay out the gardens, which included redwoods, monkey puzzle trees and two North American species of conifers in close proximity to each
other – Monterey cypress and Nootka cypress.
 In May 2008, UK resident Christine Wright won a 24-year legal battle to have her neighbour’s leylandii trees cut down for blocking sunlight to her garden.
Even on sites of relatively poor culture, plants have been known to grow to heights of 15 metres (49 ft) in 16 years.
A hardy, fast-growing natural hybrid, it thrives on a variety of soils, and sites are commonly planted in gardens to provide a quick boundary or shelter hedge, because of
their rapid growth.
‘ The hybrid has since arisen on nearly 20 separate occasions, always by open pollination, showing the two species are readily compatible and closely related.
 Description A large, evergreen tree, Cupressus × leylandii reaches a size between 20 and 25 m high, with its leaves giving it a compact, thick and regular habit.
However where the parents are treated as being in different genera, Leyland cypress becomes an intergeneric hybrid: if Nootka cypress is within Chamaecyparis, the name of
the hybrid becomes ×Cupressocyparis leylandii, and where it is treated as Xanthocyparis, the hybrid becomes ×Cuprocyparis leylandii.
Leyland cypress trees are commonly planted to quickly form fence or protection hedges.
In California’s Central Valley, they rarely live more than 10 years before succumbing, and not much longer in southern states like Alabama.
Commercial nurseries spotted the plant’s potential, and for many years, it was the biggest-selling item in every garden centre in Great Britain, making up to 10% of their
It has become clear, however, that when the genus Cupressus is defined to include Chamaecyparis, it is paraphyletic unless it also includes Juniperus.
 He further developed the hybrid at his new home, and hence named the first clone variant ‘Haggerston Grey’.
 Their rapid, thick growth means they are sometimes used to achieve privacy, but such use can result in disputes with neighbours whose own property becomes overshadowed.
 It may be added that attempts to cross Nootka cypress with other Chamaecyparis species have been universally unsuccessful.
[‘Mark A. Garland; Gerry Moore (2012). “×Hesperotropsis, a new nothogenus for intergeneric crosses between Hesperocyparis and Callitropsis (Cupressaceae), and a review of the complicated nomenclatural history of the Leyland cypress”. Taxon. 61 (3): 667–670.
2. ^ John Hillier; Allen J. Coombes, eds. (2007). The Hillier Manual of Trees & Shrubs. David and Charles. p. 436. ISBN 9780715326640.
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6. ^ Ian Whitehead (June 13, 2013). “”Turbinia” at speed – but who’s on the conning tower?”. Tyne & Wear Archives & Museums. Retrieved June 19, 2013. This examines
Charles Leyland’s connections with the sea and Northumberland.
7. ^ Armitage, James (2011). “The fertility of leyland cypress”. Plantsman (Lond.). 10: 254–256. Retrieved Feb 11, 2015.
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Li; Keith, Rushforth; Robert, Adams (2014). “Nuclear and Cytoplasmic DNA Sequence Data Further Illuminate the Genetic Composition of Leyland Cypresses” (PDF). Journal of the American Society for Horticultural Science. 139 (5): 558–566. doi:10.21273/JASHS.139.5.558.
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9. ^ Jump up to:a b “Cupressocyparis leylandii” Archived 2012-06-04 at the Wayback Machine zipcodezoo Accessed 9 March 2009
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11. ^ Gerd Krüssmann (1995). Manual of Cultivated Conifers. Portland, Oregon: Timber Press. p. 101. ISBN 9780881920079.
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3-87815-086-5, S. 256 – 257.
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Journal of Botany. 91 (11): 1872–1881. doi:10.3732/ajb.91.11.1872. PMID 21652334.
14. ^ Damon P. Little (2006). “Evolution and circumscription of the true cypresses (Cupressaceae: Cupressus)”. Systematic Botany. 31 (3): 461–480. doi:10.1600/036364406778388638.
15. ^ Kangshan Mao; Gang Hao; Jianquan Liu; Robert P. Adams; Richard I. Milne (2010). “Diversification and biogeography of Juniperus (Cupressaceae): variable diversification rates and multiple intercontinental dispersals”. New Phytologist.
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(2006). “Proposal to conserve the name Xanthocyparis against Callitropsis Oerst. (Cupressaceae)”. Taxon. 55 (1): 229–231. doi:10.2307/25065550. JSTOR 25065550.
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neighbours at war revealed to have its accidental roots in Wales”. Western Mail. Retrieved November 30, 2008.
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15 April 2020.
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Photo credit: https://www.flickr.com/photos/filtran/2951375433/’]