Information on California Dogwood Tree
California dogwood (Cornus nuttallii, abbreviated as C. nuttalli) is more commonly termed "Pacific dogwood." You will also see it as "mountain dogwood," "mountain flowering dogwood" or "Western dogwood." To confuse matters further, another dogwood variety, C. sericea, is sometimes termed C. californica or "California dogwood." It has some similar features to C. nuttalli, but it is somewhat smaller, has less attractive flowers and is more of a swamp plant. "California dogwood," however, is used interchangeably with "Pacific dogwood" to refer to C. nuttalli. California dogwood is a multibranch tree or shrub. It is deciduous, shedding annually, and is native to North America. Does this Spark an idea?
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Appearance
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Four-petaled flower of a California dogwood. California dogwood averages heights of 20 to 70 feet in natural settings when mature. The tree produces white flowers; while the leaves may turn orange or yellow, and the berries red. A cone-shaped crown may develop with some trees, and with others, a rounder crown.
Growing
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A healthy California dogwood tree tolerates drought quite readily. Thirty-percent sunlight is optimal, but the tree will grow in much more sunlight or much less. California dogwood has a low frost tolerance.
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Dogwood Anthracnose
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California dogwood is disturbed by dogwood anthracnose, a fungal disease thought to be caused by the anthracnose fungus, Discula sp. Harmful fungus can enter the tree through holes in the bark, so be careful not to damage older trees. The fungus is most active in late spring and early summer, causing blotches on leaves and defoliation, among other problems.
The disease has spread to trees in California, Washington, Oregon, Idaho and British Columbia. According to the U.S. Forest Service, the disease threatens the native Pacific/California dogwood population as a whole. Reports to the U.S. Forest Service contend that the California dogwood was almost wiped out by the fungus in the 1980s, but conditions have improved for the population since that time. However, the population in Idaho is still severely threatened, and for some time a situation existed where trees only reproduced asexually. It is at present unclear whether and to what extent the Idaho situation has improved since the 80s.
Caring for Infected Trees
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It is important to water an infected tree well in drought conditions, even if a healthy tree would not have needed the water. Other steps that can be taken include improving air circulation around trees and watering at the base rather than getting tree leaves wet. Wet leaves can harbor infections, according to the U.S. Forest Service.
Habitat
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California dogwood is most common in two areas: The first is a 200-mile swatch defined by the Pacific Ocean to the west, Los Angeles County to the south and northern British Columbia to the north. Second is an area in Idaho along the Lochsa and Selway rivers. California dogwood is found in Douglas-fir forests in California and elsewhere. It is also found in ponderosa pine forests.
Regeneration Processes
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According to the U.S. Forest Service, California dogwood has two regeneration processes, one asexual, through sprouting, and the other sexual. There is disagreement in the scientific literature concerning how many seeds are produced, and it may vary quite a bit from year to year. Seeds are spread via birds and small mammals, as well as by wind and other means.
Medical Uses
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California dogwood, C. nuttallii, is sexually compatible with C. florida and C. kousa, so that hybrid dogwoods may form. There are around 55 species of dogwood (Cornaceae). Many are used in Native American medicine, including Pacific/California dogwood. Researchers at Rutgers University believe that some dogwood may be used for anti-malarial medicine, although it is not clear whether California dogwood might be so used.
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References
- Photo Credit Flowering dogwood image by Christopher Martin from Fotolia.com dogwood bloom image by Jon Yuschock from Fotolia.com
