Chamaecyparis lawsoniana

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Chamaecyparis lawsoniana
Old-growth stand of C. lawsoniana in California

Near Threatened (IUCN 3.1)[1]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Pinophyta
Class: Pinopsida
Order:
Cupressales
Family: Cupressaceae
Genus: Chamaecyparis
Species:
C. lawsoniana
Binomial name
Chamaecyparis lawsoniana
Natural range of Port Orford cedar

Chamaecyparis lawsoniana, known as Port Orford cedar

native to Oregon and northwestern California, and grows from sea level up to 4,900 feet (1,500 m) in the valleys of the Klamath Mountains
, often along streams.

Description

A large evergreen tree, specimens mature up to 200 ft (61 m) tall or more, with trunks 4–7 ft (1.2–2 m) in diameter, exceptionally 8–9 ft (2.4–2.7 m).[4] The bark is silver-brown, vertically furrowed, and 6–10 inches (15–25 cm) thick near the base.[4] The foliage is arranged in lacy, flat sprays with a feathery appearance,[4] usually somewhat glaucous (i.e. blue-green) in color. The leaves are scale-like, 18316 inch (3–5 mm) long, with narrow white markings on the underside, and produced on somewhat flattened shoots. The foliage gives off a rather pungent scent, not unlike parsley. The seed cones are globose, 932916 inch (7–14 mm) in diameter, with 6–10 scales, green at first, maturing brown in early fall, 6–8 months after pollination. The male cones are 18532 inch (3–4 mm) long, dark red, turning brown after pollen release in early spring. The seeds fall quickly and can float on water.[4]

Old specimens lack branches near the base and often have dead tops. They can live up to about 600 years of age.[4]

Taxonomy

The species was first discovered (by European Americans) near

FRSE[5] of the Lawson & Son nursery in Edinburgh, Scotland, after whom it was named as Lawson Cypress by the describing botanist Andrew Murray. The United States Department of Agriculture officially calls it by the name Port Orford cedar,[2]
as do most people in its native area, but some botanists prefer to use the name Lawson cypress (or in very rare instances Port Orford cypress) instead. The name "Lawson's cypress" is widely used in horticulture.

Distribution and habitat

The species is

native to southwestern Oregon and northwestern California, and grows from sea level up to 4,900 feet (1,500 m)[4] in the valleys of the Klamath Mountains, often along streams. It fares best at the north end of its range.[4]

Ecology

The thick bark provides resistance to wildfires, and the species regenerates well on disrupted land in a variety of soils, but requires consistent moisture. It is

white fir.[4] The old-growth population near Coos Bay, Oregon, was wiped out by logging and wildfires in 1867–1868, and again by fire and root disease in 1936.[4]

Disease

In the wild, the species is seriously and uniquely threatened by a root disease caused by the oomycete pathogen, Phytophthora lateralis, accidentally introduced in the early 1950s following the fungus's arrival to the Pacific Northwest on nursery trees.[4] This disease is also a problem for horticultural plantings in some parts of North America. The tree is sometimes killed, though less often, by other species of Phytophthora.

Phytophthora lateralis infection begins when mycelium, from a germinated spore, invade the roots. The infection then spreads through the inner bark and cambium around the base of the tree. Spread up the trunk is generally limited. Infected tissue dies and effectively girdles the tree. Large trees are more likely to be infected than small trees due to larger root areas (although all trees at the edges of infected streams will eventually succumb). However, large trees can often live with the infections for a longer duration (up to several years).

C. lawsoniana in streamside populations are highly susceptible to P. lateralis infection. However, the rate of fungal spread through populations in dry upland areas appears to be slow. P. lateralis spreads through water via mobile spores (zoospores). The fungus also produces resting spores (chlamydospores) that can persist in soil for a long period of time. New infections generally begin when soil is transferred from an infected population to a non-infected population via water, human or animal movement.[4] After initial infection in streamside populations, secondary spread via zoospores quickly infects all downstream individuals.

Human facilitated spread is thought to be responsible for most new, and all long-distance, infections. Soil on vehicle tires, especially logging trucks and other off-road vehicles, is considered the most pressing problem due to the volume of soil that can be carried and the traffic rate in and between susceptible areas. Spread on boots and mountain bike tires has also been suggested and probably contributes to new infections locally.[6] Animal-facilitated spread is thought to occur, but is localized.

The United States Forest Service and Bureau of Land Management attempt to prevent Phytophthora spread through road closures, monitoring, research and education. Research has focused on determining the dynamics and mechanisms of spread, as well as attempts to breed resistant trees. One solution against Phytophtera is known generically as Mancozeb and also commercially known as Dithane (C). Commercial preparations of the parasitic fungus Pythium oligandrum are licensed for pest control, and documented to predate many species of Phytophthora.[7]

Similar species

The extinct Eocene species Chamaecyparis eureka, known from fossils found on Axel Heiberg Island in Canada, is noted as resembling C. lawsoniana and C. pisifera.[8]

The associated genus Calocedrus (incense-cedar) has thick orange-brown bark and the bark of Thuja plicata (western redcedar) is comparatively thin; both have different foliage than Port Orford cedar.[4]

Cultivation

Chamaecyparis lawsoniana thrives best in well-drained but moist soils, in a fairly sheltered position in full sun. Several hundred named

cultivars of varying crown shape, growth rates and foliage color have been selected for planting in parks and gardens. In the United Kingdom (UK) the following have gained the Royal Horticultural Society's Award of Garden Merit (confirmed 2017):[9]

Name Height (m) Spread (m) Shape Foliage Colour Ref.
'Aurea Densa' 1.5 1.0 broadly conical yellow-green [10]
'Chilworth Silver' 2.5 1.0 broadly columnar silver-blue [11]
'Dik's Weeping' 12.0 4.0 columnar, weeping blue-green [12]
'Ellwoodii' 8.0 4.0 columnar grey-green [13]
'Ellwood's Gold' 4.0 1.0 columnar yellow/grey-green [14]
'Ellwood's Pillar' 2.5 1.5 narrowly columnar grey-green [15]
'Fletcheri' 12.0 4.0 columnar grey-green [16]
'Gimbornii' 2.5 2.5 rounded grey-green [17]
'Golden Wonder' 20.0 4.0 columnar yellow-green [18]
'Grayswood Feather' 4.0 1.5 narrowly columnar green [19]
'Green Globe' 0.3 0.3 rounded dark green [20]
'Imbricata Pendula' 8.0 4.0 conical, weeping, pendulous green [21]
'Kilmacurragh' 12.0 4.0 columnar dark green [22]
'Lanei Aurea' 8.0 2.5 columnar yellow-green [23]
'Little Spire' 2.5 1.5 conical dark green [24]
'Minima Aurea' 1.0 1.0 conical yellow-green [25]
'Minima Glauca' 2.5 2.5 rounded blue-green [26]
'Pembury Blue' 12.00+ 8.00 conical blue-green [27]
'Pygmaea Argentea' 2.5 1.0 rounded cream/blue-green [28]
'Stardust' 4.0 1.5 columnar yellow-green [29]
'Summer Snow' 2.5 1.5 conical cream/green [30]
'Triomf van Boskoop' 25.0 8.0 broadly columnar grey-green [31]
'Wisselii' 12.0+ 4.0 narrowly conical blue-green [32]
'Wissel's Saguaro' 6.0 1.0 narrow, upright blue-green [33]

Uses

The species was discovered by Euro-Americans in the 1850s. The

Venetian blinds, and other uses.[4] Quality specimens eventually began to be shipped almost exclusively to East Asia, where it is highly valued.[4] Large amounts have been exported to Japan where it is used in making coffins, shrines, and temples.[34] Its lumber is known for its highly fragrant ginger aroma, caused by an oil which repulses decay and insects, including termites; this oil has been used as an insecticide.[4] Due to the straightness of its grain, it is also one of the preferred woods for the manufacture of arrow shafts. It is also considered an acceptable, though not ideal, wood for construction of aircraft.[35]

The wood is considered more than acceptable for use in stringed instruments. Its fine grain, good strength and tonal quality are highly regarded for soundboards in guitar making.[36]

Gallery

  • Foliage with cones: immature seed cones below, pollen cones above
    Foliage with cones: immature seed cones below, pollen cones above
  • Male cones in spring with diagnostic red colour
    Male cones in spring with diagnostic red colour
  • Mature female cones
    Mature female cones
  • Cultivar 'Imbricata Pendula', Rosemoor, Devon, UK
    Cultivar 'Imbricata Pendula', Rosemoor, Devon, UK

See also

  • Cedar wood

References

  • Snyder, Gary. 1999. "The Gary Snyder Reader". Counterpoint.
  1. . Retrieved 13 November 2021.
  2. ^ a b USDA, NRCS (n.d.). "Chamaecyparis lawsoniana". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 22 March 2015.
  3. ^ BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
  4. ^ .
  5. (PDF) on 2016-03-04. Retrieved 2017-03-28.
  6. ^ Soden, Tabitha (October 19, 2015). "Roads in the Six Rivers National Forest close to prevent spread of root disease". Times-Standard. Eureka, Calif. Archived from the original on 20 August 2017. Retrieved 8 September 2016.
  7. ^ Plato Roberts, Amy. "Biopesticides Fact Sheet" (PDF). epa.gov. Retrieved 10 February 2018.
  8. .
  9. ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 16. Retrieved 24 January 2018.
  10. ^ "Chamaecyparis lawsoniana 'Aurea Densa'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  11. ^ "Chamaecyparis lawsoniana 'Chilworth Silver'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  12. ^ "Chamaecyparis lawsoniana 'Dik's Weeping'". RHS Gardening. Royal Horticultural Society. Retrieved 2013-01-28.
  13. ^ "Chamaecyparis lawsoniana 'Ellwoodii'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  14. ^ "Chamaecyparis lawsoniana 'Ellwood's Gold'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  15. ^ "Chamaecyparis lawsoniana 'Ellwood's Pillar'". RHS Gardening. Royal Horticultural Society. Retrieved 26 January 2018.
  16. ^ "Chamaecyparis lawsoniana 'Fletcheri'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  17. ^ "Chamaecyparis lawsoniana 'Gimbornii'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  18. ^ "Chamaecyparis lawsoniana 'Golden Wonder'". RHS Gardening. Royal Horticultural Society. Retrieved 17 July 2020.
  19. ^ "Chamaecyparis lawsoniana 'Grayswood Feather'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  20. ^ "Chamaecyparis lawsoniana 'Green Globe'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  21. ^ "Chamaecyparis lawsoniana 'Imbricata Pendula'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  22. ^ "Chamaecyparis lawsoniana 'Kilmacurragh'". RHS Gardening. Royal Horticultural Society. Retrieved 21 January 2018.
  23. ^ "Chamaecyparis lawsoniana 'Lanei Aurea'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  24. ^ "Chamaecyparis lawsoniana 'Little Spire'". RHS Gardening. Royal Horticultural Society. Retrieved 21 January 2018.
  25. ^ "Chamaecyparis lawsoniana 'Minima Aurea'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  26. ^ "Chamaecyparis lawsoniana 'Minima Glauca'". RHS Gardening. Royal Horticultural Society. Retrieved 21 January 2018.
  27. ^ "Chamaecyparis lawsoniana 'Pembury Blue'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  28. ^ "Chamaecyparis lawsoniana 'Pygmaea Argentea'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  29. ^ "Chamaecyparis lawsoniana 'Stardust'". RHS Gardening. Royal Horticultural Society. Retrieved 21 January 2018.
  30. ^ "Chamaecyparis lawsoniana 'Summer Snow'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  31. ^ "Chamaecyparis lawsoniana 'Triomf van Boskoop'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  32. ^ "Chamaecyparis lawsoniana 'Wisselii'". RHS Gardening. Royal Horticultural Society. Retrieved 30 January 2018.
  33. ^ "Chamaecyparis lawsoniana 'Wissel's Saguaro'". RHS Gardening. Royal Horticultural Society. Retrieved 21 January 2018.
  34. ^ Snyder 1999 pg. 225
  35. ^ Kroes, Watkins, and Delp: Aircraft Maintenance and Repair, sixth edition, page 66, McGraw Hill, 1993
  36. ^ "Port Orford Cedar tops". Luthiers Mercantile International, Inc.

Further reading

External links