Ants are crucial in spreading wildflower seeds

May 25, 2018
  • By Charles Seabrook
  • For the AJC
These trillium seeds have attachments called elaiosomes (white parts of seeds), which are rich in fats. The elaiosomes attract ants, which spread the trillium seeds and those of other early spring wildflowers that also contain elaiosomes. Douglas W. Jones/Wikipedia

The trilliums, violets, hepatica, rue-anemone, Dutchman’s breeches, bloodroot, trout lilies and dozens of other “spring ephemeral” wildflowers that bloomed so beautifully and lushly in early spring are fast disappearing now.

They’re vanishing into the forest floor almost as quickly as they sprung up in the woods in early March and April. By early June, there will be few or no traces of the wildflowers until they re-emerge next spring.

But such is the way of spring ephemerals, which emerge quickly in spring on the floor of rich, undisturbed woodlands, before hardwood trees leaf out, and then die back to their underground parts after a short growth spurt and seed production.

Then, the ants take over. While spring ephemerals primarily are pollinated by bees, wasps, beetles and other insects, they rely on woodland ants to spread their seeds May through July. (Seed-dispersal by ants is called myrmecochory.)

To entice the ants, seeds of spring ephemerals bear external fat-rich attachments called elaiosomes, which woodland ants love. The ants carry the seeds back to their nests and feed the elaiosomes to their larvae. The unharmed seeds, now free of elaiosomes, are tossed by the ants onto well-aerated, nutrient-rich discard piles — ideal seedbeds. In effect, the ants plant the seeds.

On average, an ant carries a seed only about six feet from the parent plant. However, the seed benefits by having a favorable spot in which to germinate. In addition, by being in an ant nest, the seed is less likely to be eaten by predators such as mice.

Other plants, of course, have come to rely on other seed-dispersal strategies. Winged seeds are scattered by wind and water; seeds of berry and fruit plants are sown far and wide by birds and mammals; rough, sticky seeds are spread by clinging to fur and feathers.

IN THE SKY: From David Dundee, Tellus Science Museum astronomer: The moon will be full on Tuesday. Mercury is low in the east just before sunrise. Brightly shining Venus is in the west just after dark and sets about two hours later. Mars and Saturn rise in the east around midnight. Saturn will appear near the moon on Thursday. Jupiter is in the east at dusk and will appear near the moon on Sunday.