a picture of fern on leaf

a picture of fern on leaf

A swarm of weird plants clings to a stump high in the trees. They resemble a massive tangle of floppy, green antlers. Brown, disc-shaped plants grow beneath their fork-shaped fronds, closer to the center of this rich knot of vegetation. These are also ferns. They even belong to the same species. These individuals establish a community when they get together.

Ferns and Ants

We observe this sort of civilization in animals, specifically bees, termites, and ants. Staghorn ferns and maybe other plants appear to cooperate. Each performs distinct duties that benefit their civilization as a whole.

Kevin Burns is a scientist at the University of Victoria in Wellington. It is located in New Zealand. He first saw the ferns while working on Lord Howe, a remote island between Australia and New Zealand. He made notes on the native island epiphytes (EP-is-bytes). We call plants that grow on other plants parasites. And one species piqued his interest. The staghorn fern (Platycerium bifurcatum) is found on the mainland of Australia and Indonesia.

“I realized,” says Burns, “that these plants never appear alone.” Some of the more significant clusters were enormous. There were hundreds of people in them. And Burns quickly recognized that “each of those folks was doing something different.”

The fern colonies, he compares to an upside-down umbrella. Rainwater looked to be directed to the cluster center by some with long, green, waxy “strap” fronds. The spongy disc-shaped brown “nest” fronds absorbed the moisture.

Burns compared the entire town to a termite mound. Those mounds serve as a collective resource storage facility. Diverse individuals of the termite colony perform various duties inside it.

Eusocial Societies

Scientists call such cooperative societies eusocial (Yu-SOH-shul). Castes of overlapping generations coexist, with each fulfilling a particular duty. Some eusocial animals may be diligent workers. Others may work as nurses or nannies.

Specific insect and crustacean communities and two kinds of mole rats have been described as eusocial. Burns questioned if ferns were also eusocial.

According to his team’s statistics, they are. These ferns are a sophisticated civilization with interconnected units. Burns and his colleagues published their surprise result in Ecology on May 14th.

Ferns reproduce by spores. These grow on the undersides of leafy fronds. Four out of every ten fronds in the examined staghorn fern communities were unable to reproduce. They were primarily used as nests by other animals. Another fern features fronds known as “straps.” It did produce viable spores. This implies a separation of effort between fronds that build nests and those that do not.

Tests have also shown that nest fronds absorb more water than strap fronds. Earlier research by other scientists had discovered root networks that ran throughout the colony. Nest fronds can use them to distribute their water, quenching the thirst of adjacent strap fronds.

Examining Colonies

Burns and his colleagues also examined the DNA of ten staghorn colonies on Lord Howe Island. Eight of them housed genetically identical people. Only two colonies had individuals with different genotypes. In colonies of eusocial insects, there is a high degree of genetic relatedness. Many sisters, for example, contribute to the survival of their home nest in ants and bees.

Burns argues that many of the boxes necessary to support the claim that they too are eusocial are checked by the newly identified staghorns’ features.

Scientists had previously thought that eusocial colonies coordinate their members’ activities to satisfy the community’s standard requirements. Tasks appear to be deliberate and need thinking. However, witnessing eusocial plants “seems to imply to me that this sort of shift in the evolution of complexity does not require a brain,” according to Burns.