The plant world has numerous, amazing examples of resilience. Cycads, for example, are fascinating ancient plants thought to have evolved from ferns. Having been around for nearly 300 million years, they are models of longevity and hardiness.

What are cycads? Think dinosaurs and the Jurassic period, which was so dominated by cycads that it is sometimes referred to as the Age of the Cycads. They are among our oldest plants and precede the flowering plants. Their former preeminence is indicated by the wide distribution of cycad fossils on every continent, even places that would now be inhospitable to them such as Antarctica. This is one piece of evidence we have that the globe was formerly more hot and humid, given the preference of cycads for tropical environments.

Despite their previous eminence, however, today they are living fossils as other more evolved plants such as the flowering plants have come to take their place. These days, they survive only in small, scattered populations in tropical and subtropical environments, most of them in biodiversity hotspots like Australia, Mexico, and South Africa. They live a long time, on the order of hundreds of years. However, most species are threatened in their natural environments, often due to habitat loss and overharvesting.

Their endangered status has conversely led to their increase in popularity among houseplant collectors. Cycads are well-suited as landscape plants or houseplants depending on variety; in fact, they are superior to palm trees because they are smaller and grow much more slowly. Unfortunately, some of this newfound interest has contributed to their further decline in the natural environment due to illegal harvesting of wild cycad plants.

Many plants have both male and female reproductive parts on the same plant, but for cycads, the reproductive parts are on separate male and female plants, a trait referred to as dioecious. Moreover, cycad reproductive parts take the form of cones, a feature common to gymnosperms like pine and spruce trees. Cycads are also the only gymnosperms that fix nitrogen in their roots.⁠ They reproduce very infrequently, a characteristic that compounds their continuing decline and extinction.

The cycads that form symbiotic relationships with fungi in the soil have branching, coral-like roots that are home to colonies of cyanobacteria that take up and fix atmospheric nitrogen, just like legumes. This allows them to survive even in poor soil environments because they and their symbiotic partners are transforming nutrients from the air.

Although they aren’t a major economic plant, cycads have been used by humans for thousands of years for edible, medicinal, and ornamental purposes. The seeds and stems provide starch that can be formed into bakery products like bread, biscuits, and flatbreads as well as a thick pudding or porridge accompanied by meat and vegetables. Charred remains of cycad seeds have been found in caves in Australia that were inhabited by indigenous people over 5,000 years ago. Native Americans from Florida, mainly the Seminole, used the once-abundant cycad Zamia integrifolia for its edible starch for hundreds of years, and early settlers even set up mills to extract the seeds’ and stems’ abundant starch content, which was sold elsewhere as “arrowroot” flour even though this is a different plant. The last cycad starch mill closed in the early 20^th century as the Zamia cycad population declined and urbanization and human population increased.

Despite all these uses, cycads are toxic to humans and animals if ingested in large enough quantities. Many cycad poisoning incidents have been recorded around the world, and remarkably similar processes for leaching and removing the toxins have been recorded as well. The removal of toxins usually involves several rounds of leaching (soaking in and changing water), drying, or some combination thereof.

Cycads have also been featured in ornamentation in the form of leaf décor for shrines, religious holidays/festivals, and to mark gravesites; jewelry; and floral arrangements or wreaths. They also feature as the subjects of Japanese and other art traditions.

References

Mahr, S. (n.d.) Cycads. Retrieved from https://hort.extension.wisc.edu/articles/cycads/

Whitelock, L. M. (2022). The cycads. Timber Press.

By Rosalie Robison

Many know Beatrix Potter as the author and illustrator of famous children’s books like The Tale of Peter Rabbit, but there’s another side to her. Before she became known for popular children’s characters like Peter Rabbit and Jemima Puddle Duck, she drew hundreds of fungi and experimented with growing mushroom spores.

One day in 1895, Potter was drawing fungi she observed under a microscope. She became curious as to how they reproduced, whether it was the same for each species, and whether they could reproduce more than one time.

To follow up on these questions, she needed access to a place like Kew Gardens, a scientific institute for research in taxonomy, anatomy, cytology, and conservation. Kew Gardens was not open to the public during Potter’s time. Scholars needed permission from the director for admission to conduct research. Those without formal education, particularly women, were excluded. Given that she had no significant work in any botanical journal nor belonged to any science club, Potter faced a conundrum.

With the help of her Uncle Harry, a chemist, Potter eventually gained access to Kew Gardens. Although the staff at Kew did not take her seriously, she successfully germinated the difficult and unpredictable agaric mushroom as well as other fungi. Several of these spores were later germinated by a Kew cryptologist following her guidance. No one else was doing this research at the time.

Potter proposed other theories that were innovative for her time, such as the idea of mycelium. In wondering what fungi did during the winter months, she decided that they must have an underground system and could travel from one log to another in the form of mycelium.

Even more innovative were her ideas about lichens. Potter proposed that lichens were actually hybrid or dual organisms composed of fungi and algae in a symbiotic relationship. This idea was very unpopular during her time, as most botanists dismissed lichens as being a low-order plant thought to be either a simple moss or fungus. It would take another 100 years for the symbiotic nature of lichens and the hybridization of fungi to become accepted fact.

Despite her promising ideas, the director of Kew found her work inconsequential and dismissed her. She submitted her findings on spore germination in a paper, “On the Germination of the Spores of Agaricineae,” to the Linnean Society, a male-only group to which she was not permitted entry. Again, her theories were not taken seriously, and she withdrew her paper from publication.

Over the next 2 years, she produced over 70 microscopic drawings and concluded her research, going on to illustrate children’s books for which she is more well known. Although her paper was lost and her forays into the botanical establishment were rebuffed, her ideas were eventually shown to be correct. Moreover, her watercolors of fungi are so accurate that modern mycologists still refer to them to identify fungi. The mycologist W.P.K. Findley later used 59 of her illustrated fungi in his book, “Wayside & Woodland Fungi.”

Works Cited

Lear, L. (2007). Beatrix Potter: A life in nature. New York, NY: St. Martin’s Press.

Crazy fact: Nearly one of every ten species of flowering plants is an orchid. Current tallies have about 28,000 species of orchids (with many, many more hybrids and cultivars), which is twice as many bird species and four times as many mammal species.

For some reason, I have never much cared for orchids. Something about them looks fake. The tiny hair clips used to train them don’t help. But then I learned that there are far more orchids than I ever imagined and that they grow all over the world in almost every habitat, even the Arctic. More on this later. First, we need a little orchid primer.

Orchid Basics

Orchid flowers exhibit bilateral symmetry, meaning they are mirror images if you were to fold them in half. This aids pollination, which is mostly done by male bees and insects. In fact, orchids have a complex cross-pollination scheme and highly specialized pollination mechanisms. Some of them have flowers that mimic female insects to attract their male counterparts for pollination.

The lip or labellum of the orchid is the part that is usually modified to attract and direct (even trap) specific pollinators either through its color, shape (pouch, ruffles), decoration (hairs, fans, tails), or some combination thereof. It provides a landing platform for the pollinator. The column is a fusion of both the male and female parts of the flower into one combined reproductive system, which is characteristic of the orchid and differentiates it from all other flowering plants.

Yet another fun fact: Most orchids rely on developing symbiotic relationships with mycorrhizal fungi that provide necessary germination nutrients to the endosperm-absent seeds. Because the chances of finding the fungus is small, the number of seeds produced and blown away is numerous and most of them do not meet the necessary fungal symbiont.

Temperate Orchids

It was at the Ridges Sanctuary in June 2017 that I experienced a moment of orchid wonder. I was on a walking tour of this extremely unique natural environment and they started talking about all the orchids located there—in fact, up to 25 species that have been reintroduced as part of an orchid restoration project. Until then I had no idea there were orchids beyond the showy fake looking things at botanical greenhouses. This started a seed of interest for me.

In contrast to tropical orchids, temperate orchids are usually terrestrial, meaning they grow in the ground, with underground rhizomes and more subtle flowers. There are many temperate orchids that grow across North America and the Northern Hemisphere. There are about 40-50 species of orchids that grow in Wisconsin, including lady slippers, coralroot, and ladies’ tresses as well as some rare, protected species like the eastern prairie white-fringed orchid and the calypso orchid.

Have you ever heard of anything so cute as a floral pouch? Slipper orchids have slipper-shaped pouches (which are modified labella) that trap insects to force pollination. This is just one of the unique pollination mechanisms adapted by orchids. Slipper orchids are typically temperate species across the Northern Hemisphere. Some of them can even withstand extreme cold, blooming as the snow melts.

Tropical Orchids

Most tropical orchid species are epiphytic, meaning they have aerial roots and they absorb humidity and nutrients from water vapor. They grow on top of other plants rather than in the soil. Growing epiphytically allows them to reach the light or nutrients better than if they stayed on the ground. Some orchids are even lithophytes, growing on rocks.

One reason orchids are so popular is the relative ease of some orchid species at cross pollination, meaning hobbyists can produce a new orchid from two different orchid parents. The most difficult part, however, is germinating the orchid from seeds, which are almost microscopically tiny.

Orchids surround us whether we are at an orchid show at a botanical garden or out and about in the wild!

The winter cracks our perception of ourselves. The seasons toss us through cycles of wash, rinse, dry, and tumble; every year we get the same treatment even though we sense each stage in a cycle of unique moments. Nature signals familiar patterns if we look, but many of us now live a life of screens: going from big screen (TV) to little screen (phone or tablet), from bad screen (work) to good screen (home). We are looking at life as an apparition.

The signs of winter are curious and unique: splits, cracks, animal tracks, fractals, obstacles.

When there’s a fresh snow you can tell what went before you. Water shape shifts from thundersnow to ice floes to thick platforms. Blocks of ice stagnate.

Crystalline patterns of water in various states form on our windows and along our daily routes. Objects become frozen in time.

The Physics major inside me finds a lot to love. The way fresh snowfall perks up all it coats in a gentle blanket; the way moving water freezes mid-float down a river’s fall; the way intricate weather conditions conspire to coat the world in dangerous but glistening magic princess ice. The way objects poke up cutely through their white blanket.

Nature has frozen in time; space floats while time stops. My mind is numb as though all its contents have frozen mid-drip into the void. The patterns of ice intrigue me; why do they freeze in the different ways they do?

Winter affords us a different view of familiar objects. Snow nestles into the comfort of acorn shells. A sewer gate looks practically artistic. Nature’s leftovers are decorated in white lace. No other time of year can you tell where people or animals have gone as well as you can in winter.

Sometimes, snow simply gets in the way of life: Where there was space, now there’s snow. Everything left outside gets the snow treatment here. Its winter appearance is different than its non-winter appearance. Those who live in warmer parts of the world don’t experience this dichotomy.

Growing up in California, we used to just “go to the snow.” It took me over 10 years of living in Wisconsin to understand the non-optional cold and associated dress code and much longer to embrace it.

In early 2022, I took my first interstate COVID-19 era trip and had the luxury of choosing to “go to” the snow. A strange destination for someone looking to escape winter in Wisconsin, but it’s all about choice.

Disposing of your mattress is different in winter. We try to get around but it’s a lot harder. There is no swimming and no roller coaster ride. It becomes more and more difficult to move.

I love to read about the Arctic, but only in winter. You name the book or expedition, I’ve read it (My favorite: Ada BlackJack: A True Story of Survival in the Arctic. Runner up: Arctic Village: A 1930’s Portrait of Wiseman, Alaska). Why? Perhaps it’s the drama. Isn’t that why we watch crime shows and soap operas? More than that, I gain insight into how people who live in perpetual winter understand and engage with this season year round. As a summer person at heart, it helps me appreciate winter. I like learning how people cope with living in extreme conditions.

Each season coaxes a different language and personality out of me. Winter person longs for life and evidence of living; summer person is drowned in it and looking for reprieve. Winter person spends a lot of time in her head. Summer person is out of her head. Spring and fall mediate these two extremes. Spring is holy; fall is relief.

The color palette of winter curbs summer’s enthusiasm: shades of brown and beige contrast with white on a backdrop of dead, muted green. Different languages have different words for colors; languages of people living intimately with nature with little exposure to artificial colors, like ancient Greeks or Papua New Guineans, often lack words for colors like blue or purple (according to Through the Language Glass: Why the World Looks Different in Other Languages). Our eyesight adjusts to what we see on a regular basis: our world can limit our understanding of color and decision to differentiate between different hues.

Winter person’s vision has become accustomed to a palette of muted grays, browns, dirty whites, and the occasional red dogwood twig, sumac inflorescence, or burst of still-surviving green.

Winter brings into focus many things that go unnoticed in summer abundance: moss, lichen, the tentative and timid sprouts or super hardy greens that survive even under ice.

Lichen: Primordial plant blobs, a synthesis of organisms crawling less than an inch in a decade. If lichen grows that slow, does that make it OK for me to slow down? What does an inch of lichen growth see? What do I see in in comparison?

Moss and cones: Winter gives treats to direct our focus if we choose to discover its hidden worlds. The things we miss when life is abundant. The things we miss when life is scarce.

As spring approaches, the sunlight starts peering through our eyelids, waking us up out of our winter slumber. Happy signs abound.

Crisp, icey breath

My mind is playing tricks on me

While Mother Nature watches from afar

On frozen grass.

Ice crystals, cold brisk clean feeling air, snow crunch. You’ll miss winter when it’s gone.

Inhale the fragrance of coconut geraniums or spicy shell ginger, pop a citrusy kumquat into your mouth, and pretend you’re in the Mediterranean while the snowstorm rages outside. Welcome to the UWM Greenhouse, located on the UW-Milwaukee campus in Wisconsin.

I began volunteering at the Greenhouse after becoming a UWM employee in 2018. Before the COVID-19 pandemic, I would visit weekly to help with potting, dividing, propagating, pruning, grooming, and other tasks as needed. Since the pandemic, I have concentrated my efforts on managing the UWM Greenhouse Instagram account as a way to share the bounty with a wider audience while expanding my own knowledge of botany.

The UWM Greenhouse showcases biodiverse species representing the full evolutionary spectrum, from primitive mosses and liverworts to cycads to flowering plants. Rooms with different habitats, including desert and tropical, house nearly 700 plant species of over 110 plant families, including several that are rare or endangered in the wild. The collection has been maintained for more than 50 years and includes plants obtained from the wild, trades with other universities or conservatories, and seeds. The Greenhouse also includes labs that support student and faculty research.

With a wide variety of plants representing diverse ends of the plant spectrum, the Greenhouse is a great place to learn about botany. I’ve also benefited from invaluable hands-on experience and the wisdom of the Greenhouse Manager, Paul Engevold. In what follows I will share some of my favorite aspects of the Greenhouse: its rare and endangered plants, variety of primitive plants, the desert room full of cacti and succulents, and the rooftop native plant area.

Rare and Endangered Plants

The UWM Greenhouse is home to several rare, endangered, or unusual plants. In that sense, it serves as a repository for species that may be hard to find in the wild or even endangered or nonexistent in wild habitats, often due to habitat loss due to encroaching human activities.

Cabbage on a Stick

Cabbage-on-a-stick (Brighamia insignis) is a critically endangered species from Hawai’i that grew on clifftop habitats on the islands of Kauaʻi and Niʻihau. With fewer than 500 known individuals in the world, cabbage-on-a-stick is maintained in greenhouses such as the UWM Greenhouse in the hopes that it can someday be reintroduced into its native habitat. Learn more about the Greenhouse’s partner in this project at the Chicago Botanic Gardens

Corpse Plant

The evening of Saturday, April 17, 2021, was a momentous occasion: A corpse flower (Titan Arum) bloomed in the UWM Greenhouse. This endangered species has one of the largest flowers in the world and can take up to 10 years to bloom from the time it sprouts. Blooming is considered a very rare event in cultivation and even more rare in the wild. The plant is native to Indonesian rainforests but is uncommon in the wild as its native habitat is being increasingly destroyed. Only about 120 blooms have ever been witnessed in greenhouses worldwide. 

It is the smell of decaying animal flesh that gives the plant its namesake. As evening approaches, the female flowers open and the bloom heats up, trying to entice pollinators such as carrion beetles, flies, and other active night-time insects.

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Welwitschia

Quite possibly one of the coolest plants in the Greenhouse is Welwitschia mirabilis. What’s so special about this plant? It’s commonly referred to as a “living fossil” because its closest plant relatives died out long ago (see cycads, below). Endemic to the Namib desert, it consists of only two leaves throughout its entire life, which can be as long as 1,000 years or more. They are specially adapted to survive the extremely arid environment in which they live, such as being able to harvest moisture from fog and perform a unique form of photosynthesis (CAM) that occurs without opening its leaf pores, allowing it to save moisture during the hot daytime hours.

Carnivores

I would be remiss if I didn’t mention the Greenhouse’s collection of carnivorous plants such as the Venus flytrap, sundew, and pitcher plants.

The pitcher plant is, without a doubt, one of my favorites. They have modified their leaves in the shape of pitchers, which collect water and trap insect prey.

When a crawling insect brushes against one of the hairs of the Venus flytrap, the trap prepares to close. It snaps shut only if it senses additional contact less than a minute later. This way, the plant ensures that it has caught a live bug and conserves energy by not snapping shut to trap something else that it doesn’t need (like a falling leaf).⁠

The sundew (Drosera spp.) uses its sticky tentacles to catch insects for dinner.⁠ These also grow wild in some of Wisconsin’s bog habitats, such as the one shown here in Cedarburg Bog.

Primitive Plants

There are presently about 300,000 species of flowering plants in the world, representing 90% of all plant species. Flowering plants include most of those tasty fruits, vegetables, and starches that are the staples of our diet.

There was a time, however, when non-flowering plants like ferns and conifers ruled the planet. Plants such as mosses, clubmosses, liverworts, ferns, and cycads are all early forms of plants that dominated before the flowering plants took over. The UWM Greenhouse has many examples of some of these early plants.

Non-Vascular Plants: Liverworts, Mosses, and Hornworts

First came the bryophytes, which evolved from aquatic and terrestrial algae. These early plants are nonvascular, meaning, in simple terms, they have no stems. Thus, they grow low to the ground to be close to the water and nutrients they need. Think mosses as well as their lesser known cousins, liverworts and hornworts.

Early Vascular Plants: Ferns and Friends

Ferns and their cousins represented a major step up in plant evolution in that they were vascular plants: they had a plant body. The UWM Greenhouse has plenty of them.

The common Boston fern (Nephrolepis exaltata) is familiar to many. Of the common cultivated ferns, it is the most drought tolerant which makes it a very popular houseplant. The 1989 NASA Clean Air Study found that Boston ferns could filter dangerous chemicals from the air.

Other plants like spikemosses and clubmosses are more closely related to ferns, despite their name.

Early Conifers: Cycads

The UWM Greenhouse also houses several cycads. What are cycads? Think dinosaurs and the Jurassic period, which was dominated by these plants as well as ferns. Though they are less showy than other plants, they are models of longevity and hardiness, surviving more than 300 million years in small, scattered populations today. They now represent less than 0.1% of the world’s plant species, and many are protected due to rapid decline from human encroachment.

Unlike most other plants, cycads are dioecious, meaning that they produce male and female reproductive parts on separate plants (in this case, cones). Cycads are one of four still-existing types of gymnosperms which also include the Welwitschia plants mentioned above, conifers (like spruce and pine), and ginkgo trees.

The Desert Room

My favorite Greenhouse room is the desert room, where prickly, otherworldly creatures await. On one side of the room are “Old” World plants and on the other, “New” World plants. In this way, interesting patterns can be observed.

First, though, what’s the difference between a succulent and a cactus? They are closely related. All cacti are succulents, but not all succulents are cacti. “Cactus” denotes a botanical family, the Cactaceae. Most of these plants originated in the New World. Succulents are a larger group of plants that include any that have developed plant parts to store water, including cacti.⁠ Thus, the “succulent” label is more loosely defined. Many plants, regardless of origin, have developed succulent leaves or other plant parts in response to water scarcity, whether they are of New or Old World origin.

Old World Succulents

Many “Old” World species hail from Africa—southern Africa, specifically, which is one of the most biodiverse regions on the planet. Familiar succulents that originate from the south African region include jade plants, living stones, and haworthias. 

Baby’s toes or window plant (Fenestraria rhopalophylla) is native to Namibia.⁠ Each leaf has a transparent window which allows light into the leaves for photosynthesis. The plant commonly grows under sand in the wild, with only its transparent tips protruding. The plant produces optical fibers that transmit light from the “windows” to underground photosynthetic sites.⁠

Living stones (Lithops) also originate from South Africa where they have adapted unique methods for growing in harsh environments, such as growing fleshy “leaves” to retain moisture. Their stone-like appearance also helps them blend in to avoid being eaten.

The succulent Socotrian fig tree (Dorstenia gigas) grows on the Socotra Islands off the Horn of Africa. It grows a caudex—the fat, swollen trunk seen here.⁠ The flower head is a funny thing. It’s what’s called a pseudanthium or a “false flower”: Although the entire structure resembles a flower, the actual flowers are the numerous, tiny clusters on the disc-shaped center. Sunflowers and daisies are common examples of this plant phenomenon.

New World Succulents

New World succulents are primarily the cacti (Cactaceae) species of North and South America: all those spiney, pokey friends we love. The spines are actually leaves—modified leaves! Over time the leaves adapted into spines to fend off predators in the desperate environments they grow in, where food and water resources are scarce.

Rooftop: Native Plants

An outdoor rooftop terrace is home to several native Wisconsin plants. They are grown on the roof to simulate their natural weather conditions (including dormancy) and give them access to local pollinators. They remain in pots so that they can easily be moved inside to be brought out of dormancy and used for classes.

American witch hazel (Hamamelis virginiana L.) blooms in early November and is pollinated by bees, flies, and even moths. However, fertilization is delayed until May the following year. The fruits, which are contained in woody capsules, spend the entire growing season maturing until they explode in the fall and expel shiny black seeds several meters away!

Want to Know More?

For more information about the UWM Greenhouse, visit https://uwm.edu/biology/research/facilities/greenhouse/

Unfortunately, the Greenhouse is not open to the public except on rare occasions.

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To learn the latest news, follow the UWM Greenhouse Instagram account.

By Rosalie Robison

“There is a low mist in the woods—

It is a good day to study lichens.”

― Henry David Thoreau, A Year in Thoreau’s Journal: 1851

Lichen is life in its most basic form: the precursor to soil and higher plant forms.

Lichen arrived on Earth at least 250 million years ago and consists of a fungus and an alga (or sometimes a cyanobacterium) that live together in symbiosis. It has no roots, no flowers or leaves, no fruits, and no seeds but is life in its most basic form: a soil builder along with aerobic and anaerobic bacteria, earthworms, and fungi molds. Even though lichens cover only 7% of the planet’s surface, we have much to learn about them. They are interesting for several reasons:

• they are composed of two organisms in a symbiotic relationship;
• they build soil;
• they indicate air quality; and
• they have human, animal, and insect uses.

Many lichens look like and are referred to as moss even though lichens do not contain moss nor are they related to moss. A common example is Cretaria islandica or Iceland moss, which grows in grass and moss in northern and central Europe, North America, and Siberia.

Botanical Characteristics

Because they get their moisture from the air, lichens are very dependent on air humidity, and the underlying soil moisture is not as important as it is to vascular plants. They are better adapted to cold climates than any other life form and they live in some of the most extreme environments on Earth.

They are, however, highly flammable under dry conditions because they desiccate as soon as the humidity drops. Lichens often act as a point of ignition in woodlands and tundra, spreading fire. Dry lichens resemble dead litter more than live tissue. Continuous lichen mats present an uninterrupted surface along which fire spreads.

The slow growth rates of ground lichens are widely recognized and can be less than 1-2 millimeters per year. In Iceland and Sweden, lichens are commercially harvested. Up to 600 pounds are sold each year in Sweden.

Lichen varies in color from bright reds, oranges, and yellows to deep browns, greens, and grayish white, and they can change color depending on moisture. Lichen can camouflage; for example, hummingbirds cover their nests with lichen to hide them.

Two Organisms in a Symbiotic Relationship

The fungus and alga each serve a role in the relationship. How does this work? The fungus absorbs and conserves moisture which the alga uses to grow. Meanwhile, the alga shares its food with the fungus so it can survive in deserts or sub-zero climates. Together, they become something that neither organism could be alone.

Soil Builders

Lichens are pioneer species, active in the initial stages of soil formation. Lichen builds soil by building leaf mold from rock atmospheric gases and algae through the process of photosynthesis. The lichen dies and adds to the green manure of already formed soil. Initially, it is in a crust form but becomes leafy. In addition, snails, mites, and caterpillars eat lichen which supplies manure for soil making.

Lichens are pioneer plants because they are dependent on air moisture rather than soil moisture and can tolerate shallow soils. They can persist in environments too harsh for higher plants. Northern boreal forests offer climatically optimal conditions for lichen growth because of slow plant succession and little competition from other plant forms.

Air Quality Indicators

Lichens are also common indicators of air pollution or air quality. Their sensitivity to sulfur dioxide and fluoride makes them useful as an indicator of high concentrations of these chemicals. Lichens can also absorb radioactive fallout.

Human, Animal, and Insect Uses

Lichens are a source of food for humans and animals as well as for insect shelter and nesting. For example, ground lichens provide the major bulk of the winter diet of woodland caribou. Iceland moss was traditionally eaten powdered in breads, soups, cereals, jellies, and salads, and various lichens have applications in dyes, perfumes, hair tonics, soaps, and cold creams. Medicinally, lichen contains antibacterial and antiviral properties, is an antibiotic, and is used for ailments as a narcotic and insecticide.

“I thought the earth remembered me,

she took me back so tenderly,

arranging her dark skirts, her pockets

full of lichens and seeds.

I slept as never before, a stone on the river bed,

nothing between me and the white fire of the stars

but my thoughts, and they floated light as moths

among the branches of the perfect trees.

All night I heard the small kingdoms

breathing around me, the insects,

and the birds who do their work in the darkness.

All night I rose and fell, as if in water,

grappling with a luminous doom. By morning

I had vanished at least a dozen times

into something better.”

~Mary Oliver, “Sleeping in the Forest”

You can grow lichen yourself. Use a knife to scrape some from trees or rocks and let it dry in the sun. Crumble and rub it on a rock surface, then add water and a new batch of lichen will start.

Sources

A Modern Herbal, Vol. II. M. Grieve

Plantlife-online webarchive

USDA Species: Cetraria Islandica

Health Plants of the World-Atlas Medicinal Plants

Encyclopedia of Organic Gardening. F. L. Rodale, Ed.

Britannia Encyclopedia