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"In the past two months, the microbe that causes sudden oak death has been found in 61 plant nurseries in nine states, suggesting that the disease could invade forests far from its Bay Area origins. "It would change our entire landscape," said plant pathologist Anni Self of the Tennessee Department of Agriculture, which discovered three cases of sudden oak death at two nurseries.
The spread started through shipments of plants from the giant wholesale Monrovia Nursery in Azusa, east of Los Angeles. Monrovia is outside the 12-county quarantine area, including Santa Clara County, established in Northern California to contain the disease. It is not known how Monrovia's plants contracted sudden oak death.
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Monrovia sent at least 292,500 plants susceptible to the fungus to 1,200 nurseries and retail outlets in 39 states during the period it was known to have the disease, according to the U.S. Agriculture Department. Even worse, there is now evidence that Monrovia had shipped infected plants before the disease was discovered and could be stopped.
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Discovered nine years ago in an oak grove in Marin County hills, the fungus called Phytophthora ramorum has wiped out acres of forests in the most hard-hit region of the coastal Bay Area. Plants such as camellias and rhododendrons can spread the disease, which weakens but does not kill them. But it is fatal to coast live oak, black oak and tanbark oak trees. It is not known how many of America's 80 varieties of oak trees, or other species of plants, would be vulnerable to sudden oak death. The majestic southern live oaks -- many alive since before the Civil War -- are presumed to be susceptible to the disease."
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http://www.contracostatimes.com/mld/cctimes/news/state/8538741.htm