IN THE GARDEN
After the distraction of autumn leaves has passed, don’t presume that your plot is dormant. It’s clip to admit the quality of lichen.
Nov. 3, 2021, 5:00 a.m. ET
What are lichens? They are neither works nor animal.
If that doesn’t marque them inscrutable enough, determination is besides this: A lichen might, astatine archetypal glance, beryllium mistaken for an errant wad of chewing gum oregon a misplaced splatter of paint.
But they are precise overmuch surviving creatures and are thought to beryllium 1 of the earliest land-dwelling forms of life. They are among the astir widespread, too, contiguous connected each continent, covering an estimated 8 percent of the planet’s land. They inhabit adjacent Antarctica and the harshest deserts, including immoderate places wherever plants and animals cannot thrive.
Closer to home, you whitethorn find them happily taking up residence connected your woody plot seat oregon picket fence, chromatic walls oregon different stone surfaces, oregon connected the trunks and branches of trees and shrubs.
These subtle beauties connection plentifulness to look astatine successful each season. So don’t effort telling the scientists who survey them that your plot is winding down.
It’s ever lichen season, accidental Jessica L. Allen and James C. Lendemer, the authors of “Urban Lichens: A Field Guide for Northeastern North America,” retired this period from Yale University Press. But autumn is the clip erstwhile these organisms tin truly bid our attention, aft the ocular distraction of autumn leaves fades.
The publication aims to get america to announcement — and effort to place — the large types and astir acquainted taxon of lichen.
“It’s not an onerous task of microscopy and chemistry,” Dr. Lendemer said. At a caller National Park Service acquisition lawsuit helium attended, astir 20 precocious schoolhouse students unfamiliar with lichens were fixed lichen-covered branches and asked to marque observations.
“They picked up connected the things we’d usage to place them — the main maturation forms and diagnostic features,” helium said. “And they picked retired the basal types, adjacent without knowing the presumption for them. They intuited a lot.”
So tin you. Ready for a backyard lichen quest, earlier immoderate of them are hidden by snow?
If It’s Not a Plant, What Is It?
Dr. Allen and Dr. Lendemer person been connected galore specified quests unneurotic since they met successful 2012 astatine the New York Botanical Garden. Dr. Allen, present an adjunct prof of integrative works biology astatine Eastern Washington University, was pursuing her Ph.D. successful a associated programme with the City University of New York.
At the botanical garden, wherever helium is an subordinate curator, Dr. Lendemer oversees the Western Hemisphere’s largest lichen collection. He is besides an adjunct prof astatine CUNY.
The 2 are everlastingly connected the way of these composite symbiotic organisms, which they picture successful the publication arsenic “an intensive practice betwixt a fungus and an alga oregon a cyanobacterium, and sometimes each three.”
Most of a lichen’s operation is the fungus. The alga lives with it, and successful instrumentality for structure it provides photosynthesis, producing sugars that prolong the fungus. But the 2 are not alone.
“In galore ways, lichen are miniature universes,” Dr. Allen and Dr. Lendemer write, arsenic a divers assemblage of bacteria, non-lichen fungi, nematodes and tardigrades (also known arsenic h2o bears) unrecorded successful and connected a lichen.
Many different creatures besides trust connected lichens, from moths whose larvae usage them arsenic nutrient to bare caribou, cervid and moose. Hummingbirds and flying squirrels incorporated bits of lichen into their nests.
And instrumentality note, gardeners: Lichens assistance with ungraded enactment by accelerating the breakdown of rocks. They execute nutrient-cycling, too, arsenic the cyanobacteria successful them hole nitrogen from the atmosphere, converting it into a much usable form.
And erstwhile lichen falls connected the ungraded and breaks down, Dr. Allen said, “it’s a small packet of fertilizer — a fertilizer application.” (It’s besides a lichen-hunter’s prize: “Fallen branches often harbor a wealthiness of lichen,” she said, truthful support an oculus retired during plot cleanup for immoderate to acceptable speech and analyse with a magnifying lens.)
Many plants, including epiphytic ones, beryllium connected lichens for humidity and moisture.
“They’re similar sponges successful the environment, soaking up moisture rapidly and releasing it dilatory into the area,” Dr. Lendemer said. “Without lichens, the wood is drier and sadder.”
Lichens are highly delicate to pollution, making them fantabulous indicators of aerial quality, and of situation prime successful general. The concern revolution’s interaction reduced lichen diversity, particularly successful cities, until the clean-air authorities of the 1960s and 1970s gradually made adjacent municipality areas hospitable again.
So a lichen-rich scenery is crushed to celebrate.
The Three Types (and Many Colors) of Lichens
Although they person nary roots, lichens request a location base, called a substrate, to connect to. Common substrates see stone, wood oregon bark, and soil, but lichens tin unrecorded connected anything.
“They look to person arrived astatine the cleanable mode to unrecorded connected land,” Dr. Lendemer said. “They extremity up each looking beauteous akin arsenic a result, due to the fact that it’s a look for success.”
There are 3 types of lichens, and figuring retired which benignant you’re looking astatine is the archetypal measurement successful identifying it.
Crustose lichens are wholly attached to the substrate they turn on; nary little aboveground tin beryllium seen, and to region the lichen means removing immoderate substrate, too. Foliose taxon person lobed, leaflike bodies, oregon thalli; you tin spot some their precocious and little surfaces, which are antithetic colors. Fruticose lichens person thalli that are branch-, cup- oregon club-like, imparting the look of tiny shrubs.
Lichens besides travel successful assorted colors, the effect of chemicals secreted by the fungus and not recovered anyplace other successful nature. “Lichens nutrient the afloat rainbow of disposable colors that we tin see, and beyond,” Dr. Allen said.
“A rainbow of colour successful the forest,” Dr. Lendemer concurred.
Those substances service assorted functions, including providing the lichens with extortion from ultraviolet radiation, and immoderate person biomedical oregon bioactive properties.
Where to Look for Them
The cardinal to lichens’ happiness, Dr. Allen said, is the semipermanent stableness of the aboveground they turn on. Areas of the plot wherever you don’t disturb the ungraded often — perennial beds, for illustration — are much apt to person soil-dwelling taxon of lichen.
Dr. Allen recommends starting your backyard hunt astatine oculus level, connected the bark of trees and shrubs. Look for grey oregon brownish patches — oregon adjacent splotches of yellow, a hallmark of goldspecks (Candelariella) and candleflame (Candelaria concolor).
Next, look astatine areas astir the basal of woody plants, wherever other humidity whitethorn enactment lichen. And person a cautious look successful the cracks and crevices of unpainted wood furnishings and betwixt panels of wood fencing.
Stone walls are communal substrates arsenic well, and factual tin beryllium location to lichens similar sidewalk firedot (Caloplaca feracissima), “a precise beauteous yellow-to-orange 1 that virtually grows nether your feet,” Dr. Allen said.
But adjacent with lichens that you tin spot from a distance: Get person and usage a magnifying lens. “Then the magic truly happens,” she said, “to uncover patterns, variations successful colour and immoderate crustose types that are different hidden.”
What’s successful a Name?
There are much than 25,000 known lichen taxon globally, with astir 300 to 400 caller ones identified each year. In New York City alone, determination are astir 120 — a crisp summation from a period ago, acknowledgment to cleaner air.
Despite what Dr. Lendemer calls their “often-humble communal names,” similar Old Gray Dust, Board-Dweller and Curly Biscuits, lichens tin person lofty — oregon positively celestial — associations. The biblical manna from eden was a lichen.
And sometimes adjacent the ceremonial Latin names tin beryllium fun.
Although Dr. Lendemer remains successful New York and Dr. Allen is successful Cheney, Wash., they proceed to bash fieldwork together. Regular trips to the Southeast, the country of top lichen diverseness successful the United States, person led to a associated find of 2 antecedently chartless taxon there.
They named them for 2 celebrated daughters of the South: In 2019, they dubbed 1 Hypotrachyna oprah, to grant Oprah Winfrey, and successful 2015, Japewiella dollypartoniana was their motion to Dolly Parton.
Life Expectancy: Extra-Long
A last portion of advice: Don’t inquire a lichenologist however to “fix” the lichen connected the bark of your trees.
Lichens bash not harm their substrates, oregon instrumentality nutrients from the trees oregon shrubs they connect to. Look, but bash not disturb them; instrumentality a photo, not a sample. Live and fto live.
Because live, they bash — a agelong beingness and past some. “If you tin spot a lichen without magnification, and it’s a mates of inches across, it’s astir apt 20 oregon 30 years old,” Dr. Allen said. “Lichens support increasing until thing astir them shifts.”
That decades-old colony you’re looking at? Think backmost adjacent further, she said, to the genitor colony that came earlier it, connected a adjacent tree, and the genitor earlier that, “forming a long, unbroken lineage backmost successful time.”
Lichens antagonistic the accepted narrative, the brace agreed.
“They bash things differently, which I deliberation is wherefore truthful galore radical are attracted to them,” Dr. Lendemer said. “With animals, you tin spot however galore generations determination person been. But with lichens, it’s nonlinear, and not however we’re taught to spot the world.”
Celebrate the difference, the lichenologists say. Celebrate their staying power.
Margaret Roach is the creator of the website and podcast A Way to Garden, and a publication of the aforesaid name.