Anytime now, the first glimpses of green should begin to appear as the leaves of wildflowers unfurl. These first flowers bloom, set seed, and wither away by the time the trees are fully leafed-out, visible only for the few spring months of March, April, May, and June. (March 20th is the vernal equinox, or beginning of spring.) Because they are present for a short period of time in the spring, they are called spring ephemerals.

Many of our best-known mountain wildflowers are spring ephemerals. Violets, Bloodroot, Trillium, and Iris, Spring Beauty, Trout Lily, and Dutchman’s Breeches. If you want to see any of them, get ready! At lower elevations in Pisgah National Forest, the earliest violets and bloodroot should appear within the next two weeks. On higher parts of the Blue Ridge Parkway, May is the month that matters.

The plants all share characteristics in addition to their short appearance. They are long-lived, blooming year after year. They absorb sunlight on the forest floor during the few spring months between winter and summer. By summertime, the trees have expanded their leaves, intercepting the light that reaches the forest floor in winter and early spring. Instead of wasting energy maintaining leaves that no longer receive light, spring ephemerals store the energy they have made in thick roots or bulbs and wait for the next spring.  Most spring ephemerals share one other characteristic. They rely on the assistance of ants to disperse their seeds, and a complex relationship has evolved between the plants and ants.

The seeds of these ant-plants have a fleshy extension on their sides, in shape and function like an overgrown handle on the side of a teacup. The rest of the seed is hard and round. This handle, called an eliasome, allows the ants to grab it with their jaws and pull the seed along. They take the seed to their nest where they eat the tender and nutritious elaisome. The rest of the seed, too hard to consume, is discarded in the ants’ refuse pile, which is located either within or very close to the ant nest.
Eliasomes are rich in fats and in protein, and the ants search for these seeds in order to eat the eliasomes. They are a predictable and rich source of food in spring and early summer, before many other food sources are available to the ants.
The plants benefit, too. The seed is hauled away from the parent plant, where it won’t compete for light and food. It is planted in a pile of fertile compost, covered over with discarded insect corpses and other ant waste. The seeds are even protected by their association with the ant nests because few seed predators raid ant nests.

The introduction of imported red fire ants from South America, however, threatens this important relationship between plants and ants. Fire ants out-compete many native species of ants, which results in the elimination of the natives from areas with exotic fire ants. The refuse piles of fire ants do not promote germination and growth of seedlings. Finally, when fire ants collect seeds with elaisomes, they usually destroy the entire seed. Instead of a mutually beneficial relationship, only the fire ant benefits and the plants are harmed.

 Currently, fire ants are restricted to the coastal plain and piedmont of North Carolina, but are reported from every county, including the mountain counties, of South Carolina. They thrive in open locations such as fields and roadsides where their nests are warmed by sun.  As long as the forest remains intact, they rarely invade it, but as roads and logging operations open up the forest, conditions improve for this exotic ant. In addition, global warming may increase the northern extent of their range. At present, no one is able to predict if this introduced pest will invade our mountains.

Next time you see a violet, thank the native ants. And hope that they can survive the onslaught of the fire ants. Those ants aren’t just annoying to animals, they are destructive to plants as well.