MARSHALL, Calif. (AP) - One of California's rarest plants was nearly wiped out of existence when Marin County workers used a backhoe to clear a plugged roadside drain in the species' sole habitat. The Baker's larkspur, a purplish plant that blooms April through May and grows up to 2-feet tall, is found in only one place in the world: near a a drain along the Marshall-Petaluma Road in western Marin County. Last October, heavy rain pushed debris down a hillside into the culvert, backing it up and flooding the road. When county crews came out to clear the roadside drain...