Common Blue Violet
Viola sororia. The world of violets is a jumbled one. More than 75 species exist in North America, most of them natives. However, interbreeding has created many new forms and varieties, some of which only the most dedicated scientist could identify. A botanist estimated in the 1940s that about 300 violet species, varieties, and natural hybrids were living north of Mexico. Among the most common is, appropriately, the Common Blue Violet (Viola sororia), found in all states east of the Rocky Mountains. In fact, it’s so common and spreads so easily that it’s often considered a weed. While most violets employ flying insects for pollination, many spring violets also use crawling insects for a different purpose. Ants harvest and “plant” violets and certain other spring wildflowers in a symbiotic relationship called myrmecochory — literally “ant farming.” The ants are drawn to the seeds by small protuberances called elaiosomes that contain attractive fats and possibly sugars. The ants carry the seeds, sometimes as far as 70 yards, to their nests where they eat the treat on the outside of the seed. The shell, however, is too hard to open, so the ants discard the seed proper, often in a tunnel in the nest that’s used for “trash.” Here, amid nutrients provided by the soil and by the housecleaning ants, the seed has a much better chance of producing a plant than one dropped on the forest floor where it might be eaten by foraging birds and rodents. In some environments, myrmecochory also protects the seeds from destruction in wildfires.