COSTA MESA, Calif. - The thieves struck at night and knew just what they were after. In minutes, they ripped two plants from the lavish landscaping at a home in this Los Angeles suburb, then fled when the homeowner woke up and turned on a porch light. Total haul: $3,500. The thieves were after cycads, palmlike plants so prized that a rare specimen can fetch $20,000 or more on the international black market. Some species have been around since the time of the dinosaurs but are now close to extinction. The plants have been targeted in a wave of thefts...