Rhododendron occidentalewestern azalea. Grows from southern Oregon in the Coast Ranges and Sierra Nevada as far south as Monterey and Kern Counties, with disjunct populations in Riverside and San Diego Counties. Introduced into Great Britain by 1850, the western azalea became an important contributor to the gene pool the created the modern hybrid ornamental azalea. Sheepmen detest the western azalea because its leaves are sheep killers.. The California Poison Control System rates the toxicity as "Major." Rhododendrons, in general, are also said to be a source of "mad honey," a malady that exists more in folklore than in reality. Photographed at Regional Parks Botanic Garden located in Tilden Regional Park near Berkeley, CA.