In our own language the world of plants is reflected in expressions such as “to put down roots” as one of passive and enduring immobility. In fact, Coastal Maine Botanical Gardens plant curator Bill Cullina says their very survival depends on their ability to wander. This secret, itinerant life of plants is largely hidden from our view as it happens over generations, in geologic time — a scale that slips outside the view of a human lifetime. But Mr. Cullina says it is no less evolved or functional than the other great migrations.

“What’s native here now may not be geologically the next second,” he said at Polly Hill’s annual David H. Smith memorial lecture last Wednesday. “We’re just seeing a snapshot of what’s here now. Life is in a constant state of flux.”

Certain plants have come to symbolize regions of the United States — Maine’s red spruce, the sugar maple in Vermont, the palmetto palm in Florida — but it wasn’t always so.

“The idea that there is native vegetation here on Martha’s Vineyard is sort of a false concept,” he said. Using pollen core samples from bogs, paleobotanists are able to reconstruct plant communities over the millenia. Some 15,000 years ago, a relative blink in the grand scheme, our native vegetation was rare indeed, as a mile-thick sheet of ice blanketed northern New England while Martha’s Vineyard lay in a windswept tundra. The ancient tourist would have had to visit Atlanta to see anything resembling Maine’s boreal coniferous forests and southern New Englanders might have felt at home only in the deep South where mixed broadleaf deciduous forests reigned.

Bill Cullina feels a plant’s survival depends on its ability to wander. — Ivy Ashe

When viewed with the proper wide-angle perspective, the coordinated maneuvers of the plant world appear as an army, mirroring the advance and retreat of the ice caps. Plants employ a wide range of strategies to respond to changes in climate and some are more adept than others at colonization. When glaciers retreat, wind-dispersed plants, including members of the aster or poplar family, some of which can travel as far as 300 miles before settling, are first on the scene. But Mr. Cullina reserves the title of “superstars of wind dispersal” for mosses and ferns, estimating that there are five million spores on an individual fern frond and that the average person probably inhales billions of them over the course of their lifetime. The most striking example of fern flight comes from the thelypteris quelpaertensis, which thrives in British Columbia as well as 3,600 miles east, where a lone community of the plant has taken hold in the Gros Morne National Park in Newfoundland.

Other plants hitchhike, relying on birds and bees to disperse their genetic information. Bloodroot seeds release oleic acid, mimicking the stink of dead bugs. Ants retrieve the seeds and bring them back to their nest, planting them as effectively as any gardener. Such animal deliveries may only be good for a few feet but when negotiating the vicissitudes of ice ages, plants can afford to be patient.

In his own studies Mr. Cullina has observed the remarkable adaptability of plants particular to their location. After planting two samples of a New England species of viburnum that he collected — one from Maine and the other from Connecticut — in a Massachusetts nursery, Mr. Cullina was intrigued to find the southern sample thriving and the Maine plants dead after only a few weeks. The plants were separated in nature by only 150 miles.

“In the 10,000 years since they were isolated, the Connecticut plants had developed more heat tolerance,” he said.

Similarly, as a child, Mr. Cullina tried growing a white oak from seed in Hartford at a summer cottage on Cape Cod. The tree still stands but leafs out a week earlier than the local population and suffers an unsightly fungal disease.

“If you’re interested in native plants the best thing is to try to find one growing right here on Martha’s Vineyard because they will be the best adapted,” he said. “People think that evolution happened and this is what we got. But things are always evolving and that’s what’s most fascinating to me.”

As the earth’s pageant of unending geophysical change carries on, now amplified and mutated by human activity, plants will continue to respond. But some, suited only to islands of habitabilty, like the yellow-flowered Potentilla rabbinsia stranded above the tree line of New England’s White Mountains, are doomed.

In 50 years Mr. Cullina estimates the floral suite of coastal New England may more closely resemble Virginia or even South Carolina.

“It won’t be the first time that has happened,” he said. In fact, he says, that shift is already taking place.

“The stuff I see growing out here — when I look at those monkey puzzle trees, when I first came here 15 years ago, those monkey puzzle trees were barely surviving; now they’re growing like crazy,” he said. “To me that says something has changed.”