Answer: The Dragon Tree is not from the American deserts, but from the Canary Islands. It has a sap that hardens to a dark red. People call the sap "Dragon's Blood". Dragon's Blood Tree is botanically Dracaena draco. It grows slowly to 30' tall and 20' wide, grows best in full sun, with moderate amounts of water, in well-draining soil.
This is unusual enough a plant that most nurseries do not carry it. However, I found 3 places in California with Dracaena draco:
Exotica Rare Fruit Nursery in Vista (760-724-9093); Pacific Tree Farms in Chula Vista (619-422-2400); and Worldwide Exotics, Inc. in Lakeview Terrace (818-890-1915).
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