Why are Japanese maples red?

Okay, Mrs. Cutman and I were enjoying the spring colors and especially a bright red Japanese maple that belongs to our neighbors. She said to me, " I understand chlorophyll, but how does this tree, whose leaves are bright red, convert solar energy, when chlorophyll is supposed to be green?". Ordinarily, I have answers for questions like this, but this time-absolutely nothing. Aware of the vast aggregate of knowledge compiled here, I said, " Let’s just ask the dope." If anyone knows the answer to this question, and can explain it to a simple carpenter and his wife so that they can understand, please do tell.

The red ones definitely have plenty of chlorophyll in their leaves. It’s just visually covered up by the red anthocyanin that has been artificially selected for. Same goes for Crimson King and Royal Red varieties of Norway maples. Like most maples, some Japanese maples are just plain green.

I figured something similar. Thank you for the input, so these trees are selected and bred for their desirable features like dogs, I never new that, but it makes sense. I knew some were just green, as I had a beautiful dwarf lace-leaf that only had a small burgundy fringe around the edges. I still miss that tree. (moved) I had just never considered the chlorophyll idea before. Thanks again and Ignorance Fought!

Are these anthocyanins chemically identical to the ones found in grapes?

As a related question, why do leafy plants like kale or sorrel have purple in the leaves? What evolutionary benefit do they get from the pigmentation?

Remember that pigments reflect light. So… purple pigments might reflect potentially damaging UV light?

Various pigments might be important not so much for their color but for other properties, or maybe the color is important to help pollinators find it, or it might be a random mutation that doesn’t harm the plant and thus is not eliminated from the gene pool

Kale has been artifically bred to look the way it does - it is actually the same species (Brassica oleracea), as broccoli, spinach, and a few other things. The evolutionary benefit is that farmers kept growing it.

I think most purple-leafed plants that you see around you have been bred for that color (think purple Norway maples).

Certainly variegated-leaf plants aren’t under evolutionary pressure to look that way - typically they appear as sports which are then propagated by nurserymen, who may have to fight a strong tendency of the plants to revert to all-green leaves (less chlorophyll tends to make for a weaker plant).

If you’re into anthocyanins for purported health benefits, there are now blue-purple tomatoes coming onto the market that are high in these compounds.