In a British conker competition, players thread the seeds of horse chestnut trees on strings and try to smash those of their opponents. (Matt Dunham/AP)

Meara Sharma writes about culture and the environment. She is also a nonfiction editor for Guernica magazine and an independent radio producer.

You know the feeling. You learn about something new — say, a rare bird or an obscure novel — and then start seeing it everywhere. After I arrived in England from New York recently, a friend handed me an orb encased in tree-frog-green spikes that split to reveal a shimmering brown nut the size of a golf ball. It was the seed of a horse chestnut tree, better known as a conker, a word deeply familiar to Britons but clunkily new on my American tongue. Yet not only did I almost instantaneously begin to see these whimsical things on street corners and meadow edges, but the word itself seemed to follow me around. An advertisement for the 2017 World Conker Championships, where players thread conkers on strings and try to smash those of their opponents. Conker Club gin at a cocktail bar. A shade of lipstick, urged upon me by a saleswoman at the drugstore, called Shiny Conker.

There's a name for this phenomenon: the frequency illusion. Coined by linguist Arnold Zwicky, it is attributed to the psychological processes of "selective attention" and "confirmation bias": We fixate on what is relevant to us, and we see what we want to see. But perhaps there is another, somewhat less narcissistic, way of thinking about this sensation. When we learn new words and ideas, and then begin to see them everywhere, the world is suddenly more legible and more vivid. Language reveals to us what was always there, but to what before we may have simply passed over, we now feel intimately connected.

This is the terrain of the acclaimed English environmental writer Robert MacFarlane. A self-described "word-collector," his 2015 book, "Landmarks," compiled thousands of words and phrases from British Isle dialects that render place and landscape in precise and often delightful ways, but are largely falling out of use. Consider "ammil," the film of ice that makes branches and leaves shimmer when a freeze interrupts a thaw. Or "smeuse," a hole in a hedge left by the travels of a small animal. The book is a celebration of the richness and pliancy of language, as well as its capacity to heighten our attention to the natural world.

However, even more everyday nature words are withering on the vine. In his latest book, "The Lost Words," a collaboration with illustrator Jackie Morris, MacFarlane confronts this "thinning," as environmental journalist Michael McCarthy has it, of both life and language. A recent edition of the Oxford Junior English Dictionary excised an array of seemingly common words, including acorn, bluebell, buttercup, heron and nectar, and replaced them with words such as attachment, blog, chatroom and voicemail, explaining that children's environments have changed and OED dictionaries are "designed to reflect language as it is used." A study from researchers at Cambridge revealed that young children are significantly better at identifying Pokémon "species" than "organisms such as oak trees or badgers." Another recent survey found that out of 2,000 adults, half couldn't identify a house sparrow; yet another found a third of respondents unable to identify a barn owl and two-thirds unable to name a hawthorn tree.

“The Lost Words,” by Robert MacFarlane and Jackie Morris (Hamish Hamilton Ltd/Hamish Hamilton Ltd)

The reasons for this include technological change, urbanization and limited access to nature. But the result is a widening gap between humans and plants and creatures, a world where the environment is something vaguely "over there" as opposed to the vital, intricate fabric of our lives. This disconnection coincides with what scientists refer to as the "sixth mass extinction"; in the past 40 years, human impact has resulted in the loss of half the Earth's wildlife, and the number of species experiencing population decay has been described as "biological annihilation." Meanwhile, in a survey of the American public's policy priorities, the environment doesn't even make the top 10. The natural world is diminishing alongside our language for it, and it is crucial to consider the connection between the two.

MacFarlane's large-size and generously illustrated book retrieves 20 of the words sliced out of the Oxford Junior English Dictionary — many of which are also endangered species — and bestows upon them a kind of mythic treatment. First, an illustration confronts potential loss; with "newt," for example, we see a dried-up pond and a bare outline of the creature's body, as though stolen from the scene. Next, an acrostic poem spells out the word, captures the spirit of the lost living thing and, in language meant to be spoken aloud, conjures it back. "Ivy," for instance, reads: "I am ivy, a real high-flyer/ Via bark and stone I scale tree and spire/ You call me ground-cover; I say sky-wire."

Finally, we see the flora or fauna restored, alive and thriving in its rightful place: slick brown otters swirling through slate-blue water; a forest floor thick with bluebells.

"The Lost Words," subtitled "A Spell Book," has the trappings of a children's book. But MacFarlane and Morris insist that it is for everyone, and I might even suggest that it be for adults. Morris's watercolor scenes have a restrained lushness, as though muted by a light but pervasive fog. Her depictions of a world without — a single rumpled heron feather floating in empty space; the parched, ashen remains of a fern — are hauntingly beautiful. And MacFarlane's spell-poems, while delicious to the ear, also possess a kind of honest darkness. For "willow," for example: "We will never whisper to you, listeners, nor speak, nor shout,/ and even if you learn to utter alder, elder, poplar, aspen,/ you will never know a word of willow — for we are willow/ and you are not."

Without doom-and-gloom statistics and guilt-inducing rants, the book manages to reckon with the precariousness of our current day while evoking a visceral joy for the natural world. Its poignancy is a galvanizing force, rather than something to hide behind.

MacFarlane is among a number of contemporary environmental writers engaged in what has become known as "re-enchantment," an effort to rekindle a sense of wonder about nature. This is an easy target for criticism. What good is lyricism in a time of crisis? Why does it matter if we know the word "fizmer" (a "rustling noise produced in grass by petty agitations of the wind"), let alone "dandelion" or "raven"? Because, as the frequency illusion reminds us, language — especially vivid, exacting language — makes the world meaningful. It sharpens our vision, creates relationships between our selves and our surroundings, and, subsequently, makes us care. If we are to imagine the complex solutions that our continued existence on Earth demands, we cannot conceive of the environment as a green-brown blur, of nebulous and inarticulable importance. As the poet Wendell Berry wrote, "We know enough of our own history by now to be aware that people exploit what they have merely concluded to be of value, but they defend what they love. To defend what we love we need a particularizing language, for we love what we particularly know."

Despite innumerable dire reports and predictions, it is still vexingly difficult to communicate the gravity of what human impact on the planet has wrought and what it means for our future. Perhaps, in the face of leaders who respond to environmental catastrophe by gutting environmental protections, a vocabulary of enchantment and love, as opposed to anger and fear, is something to heed. A vocabulary that helps us identify, with clarity and spark and wonder, what we hold dear and what we thus need to fight for. A vocabulary that, with its sheer radiance, disperses the fog of careless political rhetoric — like "shivelight": lances of sunshine that pierce the canopy of a wood.

The lost words
A Spell Book

By Robert MacFarlane

Illustrated by Jackie Morris

Hamish Hamilton. 128 pp. $28.97