From The Buffalo Seed Company:
 
GOMPHRENA (Gomphrena globosa) (Flowers July-First Frost) — This globe amaranth variety consists of two colors, reddish purple with a few white flowers. We planted a multicolor variety in 2017 and in 2018 we had volunteers plants pop their beautiful heads up out of the soil. From the volunteers we collected seeds and planted again, and, voila this is the result. It is great for both fresh and dried cut flower arrangements. In the field, it is absolutely stunning to see and it brings in the pollinators. While we have not tried it, it is said to be edible and have medicinal properties.