The trout lily is a North American spring wildflower that’s cuter than its name suggests. Dappled leaves frame a little yellow blossom that keeps its face shyly toward the ground. Inside the bloom, the flower’s anthers and pollen vary from bright yellow to dark red. Researchers could find no purpose for the different colors—except, maybe, to satisfy the whims of pollinating insects.

Plenty of flowers come in multiple petal colors, and other research has explored the reasons, write Uni