I've been trying for 6 months to identify this plant. I have a young one that is about 2 feet tall. One of its interesting characteristics is the copious amounts of white milky fluid that pours forth of any wound even if one merely plucks off a leaf. Similar to jalapeno juice, it burns sensitive skin. It has stiff, thick leaves which are usually 6 inches long and 3 inches wide. I've added a photo of one I came upon in the SanDiego Zoo's arid region. This specimen was aprox. 4 1/2 feet tall. I would very much appreciate any help in naming it. Thanks!