Q: This plant grows in the garden in front of Crawford Long Hospital. Is it a coleus? The leaves and stem look similar but only the top leaves are bright red … almost like a poinsettia. It’s very showy, whatever it is.
A: You hit it right on the head with your comparison to poinsettia. The plant is Joseph’s Coat amaranth, Amaranthus tricolor, sometimes also called summer poinsettia. As the name implies, the top leaves can be a brilliant yellow, purple or red. Interestingly, amaranth is quite edible. The leaves are picked when young and boiled like spinach. Amaranth seed has been harvested for grain in South America for several thousand years. You can buy amaranth flour and baked goods at health food stores.
On the other hand, redroot pigweed, Amaranthus retroflexus, is one of the world’s worst weeds!
Joseph’s Coat amaranth