Finally, early spring has arrived! Birds are calling from still bare branches, grass is turning green, a few yellow daffodils have emerged and the clumps of purple crocuses under my fig tree are expanding by the day.

Amid the cheerful scene unfolding in countryside and towns, however, trouble is brewing. And it could come to your garden, as it did to a friend of mine’s just outside Cambridge. It may already be there.

Last year, shortly after she moved, my friend noticed a short, sturdy plant with bright yellow blossom and dark green, kidney-shaped leaves that had taken over substantial areas of her new yard. March and April was when its shiny, star-shaped flowers opened up. Now, the ground cover has shouldered out much of her lawn and her neighbor has the same trouble.

My friend calls the plant a weed. A Master Gardener identified it as the notorious invasive, fig buttercup, also known as lesser celandine and pilewort. Wake up, gardeners! This plant is sold at garden centers across the nation as an ornamental, despite appearing on the U.S. Fish & Wildlife Service’s list of invasive wetland plants, alongside rogues such as Japanese knotweed and phragmites reeds.

It’s one of the first plants to flower in spring and looks lovely until you realize what it is doing — obliterating, by crowding out, any other plants in its path.

The invasion is bad enough when it happens in a garden. We gardeners have shovels and garden forks to uproot it with, the hands-down best way to get rid of fig buttercup. Although I hesitate to suggest it, we have herbicides that will kill it, too. (My friend called a landscaper who said he’d look into which one to use.)

But imagine what’s happening in wild places across Dorchester County, our state and the entire east of the country, as well as the Midwest and some parts of the Pacific Northwest and Canada.

A website I found described how, somewhere in Minnesota, the plant started out as an ornamental in one yard, then quickly spread to cover both banks of a nearby river. And people are still buying fig buttercup to plant in their gardens!

In the wild, the invader poses a particularly grave threat to what are called “native forest spring ephemerals,” the forest wild flowers that bloom briefly in spring, before leaves appear on the trees towering above them.

Light can be scarce in the heart of a forest. Space can be a problem, once other vegetation starts growing. Native spring ephemerals evolved a way to get a head start on the competition for light and space. Then, an early-spring invasive arrived — the fig buttercup.

A herbaceous perennial, the plant emerges in winter, before most native species do, giving it a great competitive advantage. Fig buttercup stands 3 to 9 inches tall, but sometimes can grow a foot high. By June, the entire plant has gone dormant.

Fig buttercup spreads rapidly, forming “a solid green blanket ... through which native plants are unable to penetrate,” according to the U.S. Fish & Wildlife Service’s book ”Plant Invaders of Mid-Atlantic Natural Areas.” It particularly favors floodplains and spreads by finger-like tuberous roots and small white bulbs attached to the leaf stalks.

If you dig it up, make sure to get all the tuberous roots and bulblets out. If you spray it, use a systemic herbicide, but take care not to get the poison on nearby plants that you don’t want to kill.

The plant is native to Europe. I’ve seen it growing there in early spring, but never invading gardens. The trouble with plants and creatures that land in a completely new environment — as in another continent — is that no natural curbs on its growth exist there to keep it under control.

A plant that makes a tasty meal for slugs or rabbits on one continent is shunned as food on a different one, where it’s unknown. Now, if only we could figure out a way to incorporate this one into salads, we’d save money as well as our gardens and wild places.

By the way, fig buttercup’s leaves look similar to those of the native wild ginger. It could also be confused with the native marsh marigold, the wood or celandine poppy and the greater celandine. Make sure of the plant’s identity before you dig it up or spray it.

And when you’ve removed it, don’t throw the invasive on a compost heap or in a wild place. Burn it or bag it and dispose of it with household garbage.

In the meantime, happy gardening!

Editor’s Note: Laetitia Sands is a Master Gardener.