Port Orford Cedar
Native to (or naturalized in) Oregon:
- Conifer (but not a true cedar), evergreen tree, 40-60 ft (12-18 m) tall, (180 ft in wild), narrow, pyramidal, buttressed trunk. Short ascending branches, drooping at the tips. Flattened frond-like twigs are arranged horizontally, developing white "X" markings on the underside. Juvenile foliage is mostly upright, but usually congested and prickly (thin, sharp needles). Adult foliage is softer and made up of overlapping scale-like leaves. These leaves are closely pressed in opposite pairs, mostly 2-3 mm, apex acute to acuminate, lateral pair keel-shaped and overlapping smaller facial pair, glands ("a dot") usually present. Male (staminate) pollen cones on the tips of branchlets, ovate to oblong, dark brown to red at pollen release. Female flowers inconspicuous, solitary, green to blue-green, developing into seed cones that are globose (round or spherical shape), 8 mm across, blue-green then ripening to brown in the first season, with about 8 scales.
- Sun or partial shade. Prefers well-drained, moist soil; shelter from winds.
- Chamaecyparis lawsoniana (Port Orford Cedar, Lawsons Falsecypress) can be confused with Chamaecyparis nootkatensis (Alaska Cedar) . Click here for a table of distinguishing characteristics.
- Note: Chamaecyparis lawsoniana is being attacked by a root rot fungus, Phytophthora lateralis, which is devastating the species in the US (typical result). Because of this, and susceptibility to other diseases, it is difficult to grow in much of the US. Phytophthora lateralis is not wide spread in Europe and Phytophthora does not seem to be a major problem in England, since hundreds of cultivars are thriving there (Am. Nur., Aug., 1995). However, an outbreak of P. lateralis has occured in northwestern France. An online article published in Forest Pathology (15 NOV 2010) by C. Robin et al. documents the situation, it is titled; Root and aerial infections of Chamaecyparis lawsoniana by Phytophthora lateralis: a new threat for European countries. More recently, P. lateralis has been isolated from diseased C. lawsoniana at several locations in the United Kingdom (Green et al. Forest Pathology, online 4 Jul. 2012). (Also see below)
- Nearly 300 types or cultivars have been selected from this species, many more than from any other conifer (Krüsmann,"Cultivated Conifers", p. 70). Some cultivators lose their distinctive characteristics as they age, making them difficult to identify. Dr. Everett Hansen of Oregon State University developed a P. lateralis resistant clone (CF1) that is now being used by some wholesale nurseries as a rootstock for selected C. lawsoniana cultivars. Four genetic lineages of the organism have since been identified. However, Robin et al. (2015), using these lineages, found no breakdown of resistance.
- Hardy to USDA Zone 5 Native range is along the coast in southwestern Oregon (the town of Port Orford is in the center of the range) and isolated inland areas at higher elevations, e.g., Siskiyou Mountains and on Mt. Shasta in northwestern California. It is one of the four native "cedars" (so-called) in Oregon. For a comparison of the four native "cedars" see Four "cedar" species native to Oregon
- A few of its many cultivars: 'Almuii', 'Blue Surprise', 'Diks Weeping', 'Duncanii', 'Ellwoodii', 'Golden Showers', 'Green Globe', 'Miki', 'Treasure', and 'Treasure Island'
- lawsoniana: after Charles Lawson, a nurseryman in Edinburgh, Scotland, who grew trees from seed sent to him in 1854 by William Murray while working on his "Notes on California Trees'. Lawson's Falsecypress, as it is known in England and Europe, has been popular in their gardens since this first introduction.
- Oregon State Univ. campus: southeast of Ag. and Life Science building.
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