Plants are green because of chlorophyll. Some plant leaves have chlorophyll but they also have other pigments, thus they're not green, they're dark red.
What advantage does the "not greeness" give the tree?
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Anonymous2008-05-12 11:27
They're usually found on plants that live in the undergrowth. The pigment is optimized to capture energy from light that's already been picked over by clorophyll-containing plants.
Short answer: There's no advantage. Nearly all red plants were being cultivated that way (japanese maple? The japanese did it). Also, red pigments (anthocyanes to be specific) are formed because they protect young leaves, which don't have enough chlorophyll, from UV radiation. So basically all red plants have a mutation with which they can survive. The red pigments don't take any part in photosynthesis though.