As a society, we have an anosmic view of history. We don’t think about how things smelt or what olfaction meant to people in the past because olfaction is not a primary consideration in the present. When we think of the scents of the past, it is with modern snobbishness and assurance that all those early primitive people could hardly smell anything over the miasma of pre-modern filth. Nothing could be further from the truth for the Ancient Egyptians, as evidenced by their writings, art, and tomb goods. While they suffered from the same stinks that plagued urban areas for aeons, they also adored and exonerated aromatics and strongly associated them with divinity and preserving the soul in the afterlife.

“Pure, pure is the Osiris, Great of the Five, master of seats, Sishou. The perfume, the perfume opens your mouth. It is the saliva of Horus, the perfume, it is the saliva of, {///} the perfume. It is what makes firm the heart of the two lords, the perfume.”

The tomb of Petosiris
Lefebvre, Gustave Le Tombeau de Petosiris, 1924, vol.1, p.131

The First Perfume Lovers

A lot of what we know about ancient Egyptians comes from their tombs, which has skewed popular concepts of the Egyptians as death-obsessed and morose. I think it is more accurate to say that the Egyptians were sensualists whose appreciation for life was informed by an acceptance of death, as well as a rich and developed concept of an afterlife. They filled their tombs with wooden scenes and sculptures depicting everyday life as well as the accruements of daily existence, not only for use in the afterlife but as a celebration of life itself. Perfume was a big part of that celebration.

In later periods, when honouring one’s ancestors became a prominent practice, perfume was a common memorial offering. Perfuming equipment and perfume bottles were common grave goods for even those of modest means during the Ptolemaic Period. Descriptions of perfume-making, perfume application, and offering perfumed items to the gods are common motifs throughout Egyptian history in both temple and tomb art. In fact, an entire coded language in Egyptian art tells viewers what the subjects smelt like.

Let us look at the image of Sennedjem and his wife above. Hathor sprouts out of the Tree of Life, which in Egyptian art is a fig tree. Hathor is offering the food and waters of eternal life to the couple. Looks at what is just above the plate Hathor is holding. Those are four sacred Blue Lotuses and a Reed Flower, signifying that the items offered not only smell great but are, in fact, divine. As the scent of the Blue Lotus was considered holy and could consecrate divinity on things associated with it.

Also, look at Sennedjem and his wife; both are wearing perfumed wax cones on their heads. The cones have been freshly anointed with Myrrh; hence the reddish drips at the tops of the cones. Additionally, the wife’s cone has been pierced with a fragrant Blue Lotus, which may mean she pre-deceased her husband, or she just decided to throw an extra aromatic adornment on; it’s not completely clear. To an Egyptian audience, however, this would all be understood as information about the scent and spiritual state of the people present.

Temple of the Nose

It is important to remember that different cultures perceive and value olfaction differently than modern Western culture. I think we could learn a thing or two from societies that value olfaction. Ancient Egyptians lived for scent and understood their world through their noses. In their worldview, life came from breathing, and the breath of life was synonymous with the act of olfaction.

Egyptian writing is filled with allusions to scents, from talk of a lover’s sweet-smelling sigh to lengthy descriptions of the foulness of Ibis droppings in the summer sun. The ancient Egyptians’ vocabulary for odour and taste was more sophisticated than modern English, which must borrow words from other languages (like umami) to describe the sensory phenomenon when English isn’t sufficient. New Kingdom physicians identified 20 different scent categories and recognised that people often lost their sense of smell as they aged. They concluded that it was a sign that the Ba component of the Egyptian concept of the soul was already dissipating from the body.

Egyptian physicians were interested in the anatomy of the nose. Though they didn’t understand the olfactive process, they did know that the internal chambers played a part. The ancient Egyptian word for nose is fnd. From the Edward Smith Surgical Papyrus, we know that the area of the very back of the internal nose where the cribriform plate is located was called shtyt nd fnd. This has been translated since the 1950s as the inner chamber of the nose. However, shtyt is a word only used in a religious context, specifically in religious architecture, and means the dwelling place of the gods. So a better translation of shtyt nd fnd would be the nasal sanctuary.

Rene Schwaller de Lubicz argued that the layout of the original Luxor temple corresponds to a longitudinal dissection of the human head which would place the cribriform plate at the back wall of Room V, which was the Anointing Room. The place where the Pharaoh would be ritually made divine through the application of fragrances. Thereby embedding the anatomy of olfaction into sacred architecture. Schwaller goes on to state that additions to the temple system corresponded with other body parts, thereby making Luxor an anthropomorphic structure, a temple of man. I’ve yet to see conclusive data to back up Schwaller’s theory, but it is a fascinating idea. It should also be noted that Room V has been the Sanctuary to Alexander the Great since the Hellenistic invasion of Egypt. So even if earlier generations did intend this olfactive architecture, the use of Room V changed over time.

Hail, O Ye Gods Whose Odour Is Sweet

Olfaction and fragrance played a huge role in both political legitimacy and religious sanctity in Egypt. Take the below re-branding of the birth of Hatshepsut. Hatshepsut was born in a turbulent time. Her grandfather usurped the throne, and her brother/husband was only the third ruler of her dynasty. When he died young, she, as Queen, only had a daughter, her nephew by a co-wife was the only male heir. However, he was too young to rule. So, Hatshepsut became Queen Regent and eventually became sole Pharoah naming her nephew as her heir instead of co-ruler. In this unprecedented move, it was important for Hatshepsut to legitimise her reign, which she did, in part, by re-branding herself from the daughter of an upstart Pharaoh to the pleasant-smelling offspring of a god.

“He (Amun-Ra) found her (Hatshepsut’s mother) as she slept in the beauty of her palace. She waked at the fragrance of the god, which she smelled in the presence of his majesty. He went to her immediately, coivit cum ea (slept with her), he imposed his desire upon her, he caused that she should see him in his form of a god. When he came before her, she rejoiced at the sight of his beauty, his love passed into her limbs, which the fragrance of the god flooded; all his odours were from Punt.”

J. H. Breasted, Ancient Records of Egypt, Part Two, § 196

The reference to Punt is essential. Early in her reign as Pharaoh, Hatshepsut commissioned an expedition to Punt and set up trade relations with the far-off kingdom. This was a huge diplomatic success for her, showing the power and reach of the Pharaoh. It was also an economic triumph and a fragrant one, as the primary goods brought back were frankincense, myrrh, and other aromatics materials. The aromatic symbolism of this rewritten birth and expedition would have been evident to her subjects. Pleasant smells signify holiness, and the King of the Gods smells like the fragrances from Punt. Punt is viewed as the ancient Egyptians’ ancestral homeland and Amun’s birthplace. Amun is the natural father of the Pharaoh, and he gave his divine and ancestral fragrances to the Pharaoh at conception. Pharaoh Hatshepsut reaffirmed this birthright by bringing the odours from Punt to Egypt and enriching the kingdom, so clearly, she had the divine right to rule.

A Perfumed Cosmology

As we see in the Ani Papyrus and Sennedjem’s tomb, olfaction played a role in Ancient Egyptian cosmology and the concept of the afterlife, partly because the Egyptians did not associate the senses with the body but rather with the vital spark or Ka. So, of course, one could taste, see, touch, and smell after death because the Ka did not die.

Ancient Egyptian religion emphasised creating order (Ma’at) out of chaos (Isfet). They saw Ma’at personified in the progression of time and seasonality of nature. Pleasant aromas from the natural world were synonymous with Ma’at and the gods. Foul odours weren’t seen as evil, more like disordered or unbalanced. Perhaps because of scent’s ephemeral nature, fragrance and the soul are often paralleled in Egyptian mythology.

The Book of the Dead, known to ancient Egyptians as the Book of Emerging Forth into the Light, was a collection of spells and guidance for the soul in the afterlife. It was a New Kingdom best seller based on the older Coffin and Pyramid Texts. While copies varied, most Books of the Dead included the Opening of the Mouth Ceremony, The 42 Negative Confessions, and the Weighing of the Heart. Along with spells to keep away all the beasties and baddies of Duat (the underworld). What is surprising is how often olfaction is alluded to in these ceremonies and spells.

In the Ani Papyrus, the most extensive and intact Book of the Dead found, there is a feast of scent references. Ani, a new New Kingdom scribe, commissioned his beautifully decorated Book of the Dead to help guide him in the afterlife. In a treatise comprised of only 68 modern pages, the nose or nostrils are discussed six times. The burning, offering, or smelling of incense occurs 12 times. Six times the odour of the Blue Lotus is used to invoke holiness. The sweet-smelling breath of the gods has been alluded to 8 times. Discussion of the savoury smells of cooked meat happens four times. Fragrant unguents appear six times. Myrrh unguent is named explicitly as a needed item for performing the Opening of the Mouth Ceremony, which was a mandatory ritual for the dead to be able to continue into the afterlife. The Duat of the Ani Papyrus is a visually and olfactory magnificent place.

Instead of stating that the gods of the Duat bow before Osiris, it is phrased thusly:

“The Companies of the Gods praise thee, and the gods of the Duat smell the earth in paying homage to thee”

Ani Papyrus, approx. 1250 BCE Hymn of Osiris, E.A. Wallis Budge translation

More than just the descriptive landscape of the Book of the Dead, the gods recognise and evaluate human souls based on their smells. Here Anubis ushers Ani into the Hall of the 42 Judges and tells the judges he is a pretty good guy; after all, he smells godly.

“The god Anpu (Anubis) spake unto those about him with the words of a man who cometh from Ta-mera, saying, “He knoweth our roads and our towns. I am reconciled unto him. When I smell his odour it is even as the odour of one of you.”

Ani Papyrus, approx 1250 BCE, Chapter: Entering into the Hall of the Ma’ati to praise Osiris Khenti-Amenti, E.A. Wallis Budge translation

While most people couldn’t afford a custom-made book like Ani, these Books of the Dead were bought during a person’s lifetime, often with blank spaces in the spells to fill in with the owner’s name. They would have read over the scroll for years and committed it to memory.

Kyphi was burnt in every temple and most homes three times a day (morning, noon, and night). The Blue Lotus bloomed and perfumed the air every year after the inundation. Egyptians would have experienced these fragrances their whole lives. They would have associated them with Ma’at, divine cosmic order. The same order makes the Nile flood yearly and the sun travel across the sky daily. I like to think that these familiar odours, written about so frequently in the Book of the Dead, comforted those contemplating their deaths. Even in the world of jackal-headed gods and golden boats that flew in the sky, the kyphi still burned, and the Blue Lotus still bloomed.

We may never know for sure how the Egyptians felt about these smells. We do know that an ancient Egyptian would have understood their world through olfaction as much as any other sense, maybe even more so. Beyond the material world, they would have worried about the weight and scent of their souls in the afterlife.

Nuri McBride is a perfumer and writer, examining the cultural history of floral scent.  She is the Program Curator for the  Scent & Society lecture series at the Institute for Art and Olfaction.

It may be time to start thinking about other plant-based coffee-like beverages. As the effects of climate change increase, wild coffee species are under treat and many coffee-growing areas, growing primarily Coffea Arabica (arabica) and Coffea Canephora (robusta) are having to move to higher altitudes, if possible, or switch to growing more tolerant crops. As a result, coffee prices are going up and future shortages are likely. Should you be looking for a coffee alternative, one that really boosts your health without caffeine? There are a lot of plant-based beverages to try.

In her 1829 book The Frugal Housewife, Lydia Maria Child, advocated drinking a beverage made of roasted peas (English or Garden varieties) rather than expensive coffee. It’s amazing what’s in a little green garden pea.The diminutive legume is packed with vitamins A,B,C and E, zinc, and other antioxidants that strengthen the immune system and reduce inflammation, helping conditions such as diabetes, heart disease, and arthritis. They also contain carotenoids lutein and zeaxanth—great for eye health.

Consider growing a larger crop of organic garden peas this year and give a warm pea drink a try.

Pea Coffee

Take dried peas (English or garden varieties) and roast them until they turn a dark cinnamon brown.

Crush and grind as with coffee beans and brew.

Tourists from across the globe flock to Tennessee to experience the world’s country music capital and its renowned high-quality whiskey. But as Katie MacDonald and Kyle Schumann see it, an ubiquitous invasive plant species known as kudzu could become yet another state export.

MacDonald and Schumann, who became architectural fellows at the University of Tennessee Knoxville in 2019, are the co-founders of After Architecture, an architectural studio established in 2012, whose work “responds to and confronts environmental crises.” Central to their approach is repurposing invasive species for architectural use due to the immense harm caused by conventional building materials to the environment. 

Spoiled for choice in Tennessee, where invasive species run rampant, kudzu, an invasive vine, was a seemingly easy pick.

“When you talk to people in Tennessee and the surrounding states, everyone seems to have a story about kudzu,” says MacDonald. “We liked that there was a kind of recognition of kudzu. And if we could develop a way to work with kudzu, there’d be a resonance between the material itself and the public’s experience.”

Seemingly innocuous, the trifolate-leaved vine with sweet-smelling blooms was imported from Japan as an ornamental plant for the 1876 Philadelphia Centennial Exposition. Initially used as a forage crop, farmers were later encouraged to grow it as a solution to soil erosion. In the south, it found the perfect habitat — a little too perfect. 

Kudzu slithers across the earth and blankets anything it touches: grass, trees, gardens, porches, street signs, power lines, telephone poles, eventually choking the biodiversity out of an ecosystem. The hardy plant grows at the head-spinning pace of a foot per day and spreads at a rate of 150,000 acres yearly. Extremely dogged, it can adapt to most soils and climates. 

The U.S. Department of Agriculture declared it a pest weed in 1953, yet efforts to rid the country of kudzu have been largely futile, leaving individuals as well as government agencies frustrated. 

Joshua Lee, an assistant professor of architecture at Carnegie Mellon University, says he spent over $15,000 to fight a kudzu infestation in his yard in Pittsburgh, a frazzling process that included using a stump grinder to desecrate the roots before spreading black plastic across the yard for about a year. “It still comes back,” he chuckles. 

These ruthless qualities have inspired poetry and fiction paying homage to its relentlessness. Renowned Georgia poet James Dickey wrote Ode to Kudzu about the exploits of the plant in the south, in an exaggerated manner. 

In these qualities, however, MacDonald and Schumann saw a potential building resource capable of replacing the carbon-intense materials typically used in construction. “We were thinking about the hardiness. It’s really a persistent material — that’s what made it such a challenging invasive species. It’s really hard to cut away, it rolls so fast, it entangles itself with things,” MacDonald says. 

Schumann adds: “We used it as basically fibrous and loose wall assembly, and it was kind of similar to the idea of OSB (oriented strand board) which is a really standard building material.”

After Architecture demonstrated this potential with Homegrown, an art installation at the Knoxville Museum of Art in 2020, a culmination of their fellowship in Tennessee. Homegrown mimicked the skeletal form of a building. Roofless, with cut-outs for windows and a door, it was predominantly constructed with kudzu, along with a few other local invasive species like bamboo and forestry waste, all bound together by a bio-based adhesive. The 10-by-10-foot room wasn’t just an art installation, it was a reimagining of how we could build without carbon-intensive concrete, steel and aluminum. 

“When we work with something like wood, we take something large and then we cut small pieces of it away to make it into a kind of unit,” MacDonald says. “So, it’s a subtractive process. With Homegrown, we were interested in using kudzu as an ingredient and an additive formation — so adding material together instead of subtracting material away.” 

Kudzu, a “natural fiber,” is touted as a replacement for carbon fiber. Additionally, it can be used in panel materials such as sheetrock or drywall, which is typically made from gypsum that is mined from the earth. “If we can make thin panels, then they could essentially replace the interior wall surfaces,” Schumann says. 

Finding such replacements is an environmental imperative. Building materials and construction, otherwise referred to as embodied carbon, are responsible for roughly 20 percent of global emissions. These numbers may rise even further. According to a 2020 report, one in every three houses to exist in 2040 is yet to be built, and 20 years on, this is expected to double, per a Global Status Report. 

However, After Architecture’s work with kudzu is still very much experimental. As illustrated with Homegrown, it appears and feels different than most construction materials: a bit fuzzy and soft, as opposed to hard and flat. Echoing the researchers’ sentiments, Lee believes that the public is more than capable of embracing an unfamiliar aesthetic, considering the historical evolution of architecture.

“We have gone through periods of shagged carpets in the 1970s, so I don’t think it’s as foreign as it might seem on first appearance,” he says. He foresees industry and regulatory entities as more likely to resist a new,  biobased alternative to ostensibly safe, carbon-intensive materials, especially in a “highly litigious society” like the United States. It might take years of testing to ensure safety and financial viability to prospective investors. Application for the plant to be used in construction is still in development. 

“We don’t need to farm material, we don’t need to mine material,” MacDonald says. “We can actually harvest it from places where it’s already become out of control.”

Tolu Olasoji is a contributing editor at Reasons to be Cheerful. A journalist who writes on sports, culture, technology, innovation, policy, social issues, and their intersections, he is based in Lagos.

This article previously appeared in Reasons to be Cheerful.

When I read that more than a billion animals had lost their lives to bushfires still raging in Australia, I froze, staring at the incomprehensible figure on my screen. A sort of sinking feeling came. Scientists made the estimate from the numbers of animals that have died from previous land-clearing practices. It is dismaying to try to imagine all that those fires are consuming. They’ve scorched 72,000 square miles of land and over 2,600 homes, and killed just under 30 people. The animal death toll is in the trillions when you include the invertebrates. But it lifts me up to see that, with some recent rain, the situation in Victoria and New South Wales, the region in eastern Australia affected the worst, looks to be improving, however slightly. What’s more, an ancient and critically endangered species, rooted in New South Wales’ Wollemi National Park, survived the blaze.

The Sydney Morning Herald had the story as: “Incredible, secret firefighting mission saves ‘dinosaur’ trees.” The conifers, Wollemia nobilis, are uniquely wild in Australia and grow in a narrow and inaccessible gorge, the precise location of which is hidden from the public to ward off tourists and contaminants. The trees number less than 200. The effort to safeguard them from encroaching flames “was like a military-style operation,” Matt Kean, New South Wales’ Environment and Energy Minister, told the Herald. Aircraft dropped water bombs and fire retardant, and helicopters sent firefighting specialists down to irrigate the forest ground, moisturizing it to slow the fire’s spread. “We just had to do everything,” Kean said. Wollemia nobilis is like a “living dinosaur.”

Scientists have studied fossilized Wollemia dating as far back as 200 million years ago. This tree has, in a sense, outlived the dinosaurs. Encountering it can be like seeing a dinosaur-era insect encased in ancient amber brought to life. The tree’s resin (the precursor to amber) is useful to paleontologists for its chemical similarity to ancient amber (fruit flies, for instance, decay rapidly in pine resin but very slowly in Wollemia resin). Science News reported that the “living fossil” is one of the species researchers most worry might die off due to the bushfires. Having the “dinosaur” tree disappear from its natural habitat would be a blow to the amount of wonder in our world.

Calling the trees, as The New York Times did upon Wollemia’s discovery, “living fossils,” fails to appreciate them. They aren’t relics of the past, evolved for a distant time. They’ve continued to evolve, an example of adaptability; in short, they are amazing survivors. In a Nautilus article, “The Rise and Fall of the Living Fossil,” Ferris Jabr spoke to Alan Turner of Stony Brook University, an expert on fossil crocodylians and their ancestors. “I think the term ‘living fossil’ should be retired,” Turner said. “It does little good because it is almost always based on oversimplifications. ‘Living fossils’ often are judged based on some notion of overall morphological similarity. That was the case with crocs. If you squint, these various lineages all sort of look the same, but the details are all different. It ignores how evolution works on multiple levels. I wouldn’t miss it.”

Charles Darwin was playing around with the phrase in On the Origin of Species. He made clear that “living fossil” was his “fanciful” way of highlighting the more extraordinary or strange beings he encountered—ones like the lungfish and the platypus that look like they might genetically link species disparate in space and/or time. “Overall, I think the term hurts more than it helps people’s understanding of evolution,” Jamie Oaks, a phylogeneticist at Auburn University, told Jabr. “Just because a species looks similar to fossils from many millions of years ago certainly does not mean that it has not evolved. The term ‘living fossil’ is often used in cases that are simply explained by low diversity; just because there are only one or several species that represent a taxonomic group does not mean they are evolutionarily static.”

Darwin’s coinage was both “poetic and memorable,” Jabr wrote, and quickly found broad acceptance. “‘Living fossil’ was no longer a passing phrase; it had become a powerful concept shaping scientists’ attitudes toward modern species. If certain creatures were frozen in evolutionary time, the reasoning went, then they could be our windows to ancient epochs of life.” But nature doesn’t put evolution on pause. “It’s true that the living descendants of early animal lineages can teach us about their ancestors, but the idea that any species alive today has stopped evolving is simply false,” Jabr wrote. “In the last 10 years, scientists have liberated numerous species from this evolutionary straitjacket, including coelacanths, horseshoe crabs, cycads, lizard-like tuataras, and tadpole shrimp.”

When we look at a crocodile, a “primordial dragon,” Jabr wrote, “we should recognize one of evolution’s greatest survivors—a compatriot of the planet every bit as modern as we are.” The same goes for Australia’s conifer trees. With a little help from their human friends, they can continue to show us, as Jabr wrote, “There are no living fossils. Fossils cannot change; life must.” 

Brian Gallagher is an assistant editor at Nautilus.

This article previously appeared in Nautilus.

Since animals roamed the Earth and swam in its oceans, nature’s apothecary has been the local forests, fields, streams and seas. From my high school days of growing food and medicine in garden beds on some asphalt outside a trailer where we met for afterschool programming, to years of learning, working, and teaching in agriculture, my mind opened to the possibilities of how gardening can benefit health.

During the COVID shutdown when I found myself without a job and feeling a lot of emotional stress, the shift I needed came again from creating a garden, this time my own medicinal garden. As I learned as much as I could about the healing qualities of plants, I began to focus on the ones that seemed to suit my needs best. The botanicals I selected for my own mental and physical healing were ultimately influenced by one book – The Illustrated Encyclopedia of Healing Remedies by Shealy C. Norman, which guided me through the world of natural healing.

Surrounding myself with healing plants became one of my most restorative times and increased my passion for living a healthy life. Once again, planting seeds and nourishing their growth helped strengthen my beliefs in the benefits of gardening.

I realized just how essential herbs are and have been since ancient times. The ancient Egyptians and forth century BC Greek physician Hippocrates recommended willow tree bark for pain relief. In 1915 Bayer started selling it as aspirin. Bulgarian folk stories tell of rubbing the flowers of snowdrops containing galantamine on their foreheads to cure headaches. It’s now used as a treatment for Alzheimer’s disease.

As I gained experience in growing medicinal plants and making remedies, the possibilities of what a home medicinal gardener can mean expanded. We are stewards meant to help preserve and grow life, and just like the weeds, we can thrive, no matter what community or land we find ourselves in. Even though many of us live in areas of shrinking greenspaces, we must create our own environments and support the spaces bearing fruitful plant life. If you don’t have access to a ground area, a rooftop or a rare apartment backyard, there are many ways one can create a home healing garden that will serve as a physical and mental support. It can be container gardening on a small fire escape, or a window sill.

Envision your plant list as a reflection of your personality and needs. Allow the scents, colors, and textures you love to guide what you would like to see in this home oasis. You are creating a space meant to support you, your friends and neighbors. Start by creating your plant list and designing your garden with the space that is available to you.

You will want medicinal plants with the properties you need, such as easing pain, fighting inflammation, clearing congestion, aiding digestion, drawing out infection, or helping with relaxation. Look for the plants you can support the most easily with your growing conditions. Your herbal apothecary can be grown in containers placed indoors or outdoors, on porch, patio, stoop or fireescape. Growing medicinal plants in containers makes them portable and easy to adjust if in need of more or less sun exposure. If needed, consider installing a grow light.

Plants like basil or parsley added to one’s daily diet can help with circulation and heart issues. All have great healing qualities and are easy to grow, harvest, and use to make teas, poultices and salves. For a salve, combine the herb with beeswax, shea butter or a hardy oil like coconut. And there is nothing like drinking homegrown herbal tea.

Here are some great starter plants:

Lemon Balm
Applications: digestive upsets, anxiety, insomnia, sedative, flu and colds.

Chamomile
Applications: tension, anxiety, insomnia, stomachache, herpes simplex

Mint
Applications: digestive aid, upset stomach, headaches, cold and flu, cramps, tension, nausea, immune system support, congestion, athletic stiffness

Lavender
Applications: gentle antidepressant, burns, stress, sleeplessness, heartburn, indigestion, nerve pain, joint pain, muscular cramping

Oregano
Applications: sore throat, sinus inflammation, pain-relief, arthritis, wound healer, H. pylori infections, candida, athlete’s foot, skin infections, breathing issues, salmonella, staphylococcus infections, cold and flu, gum inflammation, digestive upset abdominal gas

Rosemary
Applications: memory, concentration, hair loss, stress, digestive aid, cancer prevention

Let this garden be a way to give to yourself, to the soil, and to your neighbors by sharing produce, dishes, cuttings and seeds of what you’ve grown.

Let healing start at home.

Erika Maria Aponte is an artist and farmer born and raised in The Bronx, New York. She received a certificate in agroecology and sustainable food systems from CASFS. Her work explores sustainable agriculture through community while exploring self expression through music, fashion design and food.

When I started my first garden, it was outside my high school in The Bronx with a group of other students. None of us really had experience growing, and we had not been taught to question where the food in the supermarket came from or how it was made. We built garden beds on some asphalt outside our building and learned what it takes to grow in the city. Connecting with people over a labor of love and learning what it means to grow food and medicine from a seed opened my mind to the possibilities of growth I had never imagined for myself at the time.

Many natural remedies passed down through generations have been lost alongside shrinking greenspaces. After years of learning, working, and teaching in agriculture, I started to feel like there was nothing I could do to fix things. After COVID, I was let go from my job and reflected on whether I wanted to continue to work in agriculture. It felt like my efforts would never be enough to preserve the traditions and land we were losing so quickly. I decided to leave New York City, and along the way, I came across an amazing book called the Illustrated Encyclopedia of Natural Remedies by Shealy C. Norman.

I spent the next couple of months combing through this book, learning about my ailments, expanding my knowledge about the benefits of growing plants and the tradition of natural healing. This was one of the most restorative times of my life, and it helped me strengthen my beliefs that growing is for connecting, healing, and nourishing, not just for profit. I believe we reflect the beauty that exists naturally in the world. If we would like to see more, we must cultivate the abilities that are needed to create and sustain that beauty. Then, we will always be able to grow and thrive, no matter what community or land we find ourselves in.

There are many ways one can create a home garden that will support their needs. This is truly a restorative way of healing in community because you will reflect the natural beauty that exists everywhere. In New York City, whether it’s in the rare apartment backyard or a small fire escape, allow the scents, colors, and textures you love to guide what you would like to see in this oasis that will support you, your friends or neighbors.

Envision your plant list as a reflection of your personality and needs. Some lemongrass in the fire escape could be a hint to your friends of your sweet and patient nature. I know so many people back home in The Bronx struggling with stabilizing their blood pressure. Plants like basil or parsley added to one’s daily diet can help with circulation and heart issues. Let this garden be a way to give to yourself, to the soil, and to your neighbors, sharing cuttings or dishes with what you’ve grown.

Below is a guide that will help you come up with a plant list and design your garden using the space you have been given.

A GUIDE TO STARTING A SMALL
HEALING GARDEN

This guide will help you in starting a garden in your
small yard or fire escape that will support some of
your physical and mental needs. By the end, you’ll
have what you need to start setting up your space
for some plant babies that will reflect your care
through their natural medicine and beauty.

1.

WHAT’S THE SPACE LIKE?

Amount of growing space: (eg.: 2ft by 5ft fire
escape?)
Sun Exposure:
(full sun or part shade?)

2.

WHERE ARE YOU LOOKING FOR
SUPPORT?

List your symptoms and whether you’re
looking to welcome pollinators to your
community.

3.

LIST YOUR PLANTS

Start with a small list of plants so you’re leaving
room for gradual growth. Shoot for 5-10 plants that
will be remedies for your symptoms or bring more
birds and bees to the neighborhood.

4.

WHEN/WHERE TO PLANT THEM

Practice companion planting so plants can
thrive collectively. Group your full sun plants
that need daily watering in the same spot.
Get those needing some shade and drier soil
together in a darker space.

SEED SITES!

Seed Savers Exchange Heirloom Seeds

In Northern Virginia’s land of condominiums, subdivisions, expressways and international airports, Earth Sangha’s Wild Plant Nursery lies tucked between public playing fields and a strip of woodland. In a quiet corner, it stands out as a leading source for native plant conservation. Anyone visiting each month might see over 350 varieties: ferns, milkweed, asters, boneset, sunflowers, blazing star, beebalm, phlox, violets, goldenrods, and a host of other forbs, plus grasses, shrubs, vines and trees. Almost all are propagated from seeds or spores gathered, with permission, from local parks, right-of-ways or other wild areas. In our community, if an especially rare native species needs to be sought out and saved, we know who to call: Earth Sangha.

“With extraordinary spirit” describes the amount of enthusiasm and dedication to conservation present from the nursery’s early beginning in 1977. Co-founders Lisa and Chris Bright drew inspiration from Buddhism, with a first precept, “Let us not harm but respect all forms of life.” Earth Sangha operates as a nonprofit, dedicated to growing native plants, restoring native plant communities and removing invasive species. With Asociación de Productores de Bosque, Los Cerezos, the group also supports Tree Bank Hispaniola in the Dominican Republic. There they focus on protecting tropical forests and growing local native trees, while sponsoring farms that produce shade-grown coffee within forest fragments or in restoration areas. Scientific research guides all activities, and staff and volunteers come from diverse backgrounds. Many hands contribute to the nursery’s successes. 

For people interested in propagation techniques, ongoing projects and a history of the nursery, conservation manager Matt Bright offers easy-to-understand descriptions of restoration work. Most projects occur on public land, working with teams from local government agencies to identify vulnerable native plants and select new locations for healthy growth.

He explains, “Over the past few years we’ve worked with Fairfax County Park Authority on some careful reintroduction work for Pycanthemum torreyi, which is a globally rare mountain mint species. It’s only found along the eastern U.S. It’s rare or threatened in every single state in which it occurs. There, I think, is only one population in Fairfax County…We’ve grown out some [of this species] to re-establish it into areas where it will hopefully suffer from fewer human impacts, and there will be ongoing management to prevent invasives from crowding it out.”

He draws a comparison with efforts to preserve Solidago rigida, (stiff goldenrod) a species that is rare in the state of Virginia, although more common in the Midwest and Great Plains states. The Washington metropolitan area is on the edge of its natural range.  Bright says, “We [in Fairfax County] may have unique genetics relative to other populations, in part because our populations are kind of fragmentary… we want to preserve those.”

In Fairfax County, Solidago rigida plants grew on a plot of parkland with utilities easements. Botanists had visited the area and said the plants were at risk from disturbance. Earth Sangha worked with the county by collecting seed to grow out and establish a new population. The model for reintroducing rare species is, as Bright says, “not just to amplify it and to get it out everywhere, but to make sure we have specific, proper habitat – maybe historically documented areas where it’s been.”

Documented histories of native plants in Virginia have existed since the 1700s. One of the first written catalogs was John Clayton’s Flora Virginica, published by Gronovius in 1735.

And there is the Smithsonian, in Washington, D.C., which Bright explains, “has the foremost American collection of pressed plant species… These are not just tools for botanists to true up plant ID but also historical records. So once a botanist takes a sample of a plant and they press it and they mount it, it also gets a card, saying what it is, who collected it and where they got it from. There are stacks – sheets and sheets of these things that you can look up. A lot of them are digitized now. You can get a sense of ‘Hey, we used to have this stuff around here and now we don’t.’”

He points out that all of us can make our own observations. People don’t have to live in a location for very long before they recall something they used to often see that now seems scarce.

For groups that want to head off destruction, Bright has several recommendations. Work with partners on restoration. Reduce stressors by removing invasive plants, so that native species have access to nutrients, light and pollinators. And Bright also points out the need for a community effort to reevaluate the balance of parkland between recreation and conservation activities. With very tight budgets park authorities have to focus on revenue generating activities. Bright adds, “Passive conservation doesn’t generate revenue, and it shouldn’t. We shouldn’t charge people to go for a walk in nature. The reality is that there is a lot of pressure from a lot of different constituents.”

He sees a role for everyone. “Native plant conservation on private property, that is people’s homes and gardens, commercial landscapes, HOAs, condo associations – all of that – is an absolutely necessary component… that will help reconnect our wild populations with each other.”

He goes on to say, “A lot of the species that evolved to cross pollinate with each other are susceptible to inbreeding depression, that is when populations get fragmented, the whole population size drops, and the plants as a whole become less healthy. The first signs can simply be low seed viability and that’s something we’ve experienced as growers. Some plants don’t form a lot of seed, and the seed they do form tends not to germinate. We think these are warning signs.” 

In expanding suburbs with new roadways, parking lots and more paved land, pollinators like bees, butterflies and other insects cannot visit one group of plants and then easily move to the next. Plants begin to lose their genetic interconnection. In Fairfax County, public parkland makes up a little under 10 percent of total land area. Bright advises, “Ecologists like E.O. Wilson and Dr Doug Tallamy say that a third to 50 percent of our land mass must be in conservation – has to be in native cover… We absolutely need to see that in [more] pollinator gardens and monarch way stations.”

Despite challenges, his message continues with a hint of optimism. “We’re not where we need to be… Our hope has always been at Earth Sangha, that if we can make plant conservation work here in an area where most of the economics are pointing us in the other direction – toward cutting down more forest, toward removing more wetlands, toward paving over our meadows… if we can hang on to as much diversity as we can, then there is hope for communities elsewhere in the country where the economic trends are not pointed so dramatically toward paving every square inch.” 

In our own communities, each of us can play an important role.

Visit Earth Sangha: www.earthsangha.org.

You will also want to checkout their Native Plant Compendium: https://www.earthsangha.org/compendium

After working as an architect and teaching design workshops for children, Liz Macklin became a Virginia Master Naturalist. Now she joins other volunteers in local parks pulling invasive switchgrass and looks forward to autumn mornings volunteering at Earth Sangha.

I would like to thank Lisa Bright, Matt Bright, Sarah Mard, Katie Danner and Jan Siddle for their help in making this article possible.

Before you became President of Glynwood Center for Regional Food and Farming, in Philipstown, NY, you were Director of Harvard’s Center for Health and the Global Environment. The relationship between environmental health, human health, and public policy advocacy has been your key focus and concern. What would you like to contribute and achieve at Glynwood with your leadership during these challenging times?

When I was at Harvard, I became more and more interested in the connections between the natural world, agriculture, and human health. That seems pretty obvious in terms of how we depend on nature to grow and raise our food, and we have to eat to survive, so it seems like a pretty direct connection. Yet I think there still exists a lot of disconnect between human health, public health, food, and agricultural systems in the natural world. What I hope to do at Glynwood is to prove that regional food is a model that can be replicated nationally and that a regional food system supports healthier ecosystems, human health, community health, local prosperity, and food sovereignty in a way that our centralized commodified food system is failing to do. 

Yes, our problems are interlinked and so are solutions. The past three COVID years produced a mass exodus from New York City, which has pushed up farm prices in the surrounding areas to extreme highs, pricing farmers out of business. This has become a real issue in the Hudson Valley where wealthy people are driving up farm and land prices and they don’t farm. Farmers are being displaced and leasing the land from the new owners, bringing the idea of a new type of feudal system to mind for many. Is there any dialogue within Glynwood about how to address this escalating situation?

I do think that land access is one of the main barriers to building a regional food system with small and mid-size farms that we want to see, that are traditionally practicing regenerative agriculture and fostering food sovereignty. Land access has been a problem consistently in the Hudson Valley. Because more people are buying property in the Hudson Valley, it’s been a difficult moment for land access. However, at the same time, during the pandemic, people really discovered local food. Some folks have been scared to go into a grocery store, or the centralized food supply system was so broken that they sought out local food. So, I think there’s a little bit of a buffer there.

And then there are organizations like Glynwood. We absolutely help farmers find affordable land. There are resources through Glynwood and through other partners, that make land more affordable, including no or low-interest loans, or easements on the land that make it only available to farmers or folks who want to not develop the land by putting a house on it, for example. So, there are definitely tools. There’s always more to do, but there are lots of partnerships. We work with American Farmland Trust, for example, on their efforts to match land with farmers. Increasingly, private landowners who own historic agricultural land want to see that land go back into production and might build a relationship with a farmer to be able to have a lifelong lease or a very low-interest lease on their land so that while they own the land, the owner can be a non-operating farm owner and work with a farmer that might not be able to afford their own land yet.

Do you have any success stories that you could talk about?

There are lots of success stories. One of our board members owns some farmland in the Hudson Valley and has consistent farmers on that land that run their own businesses. So, the businesses are the farmer’s businesses, and the landowner is simply a landowner. There are farms like Obercreek that we work with, where they own the farmland, and they retain the farm businesses. There are several farmers that live and work on that farm and can get high-level management skills.

Through our Farm Business Incubator program, we’ve supported several farms in the Hudson Valley that are just starting out, and some of those are pieces of land that we have helped them find through partnerships with Open Space Institute or Scenic Hudson. And we help them ensure that their farm business is viable. I know that there’s been a lot of conversation about failure stories, but there are success stories that we’ve been involved with.

Can you talk more about the regenerative agricultural movement and management movement and why it’s so important in the world right now in conjunction with everything else that’s going on, including the gathering dark clouds concerning the future of food and how we are going to feed everyone?

Regenerative agriculture is sort of a newly popularized term for a suite of practices that are pretty old. I could even argue that it’s a lot of indigenous wisdom that has been recently popularized. At its core, it’s about working with the soils to capture more nutrients and to be able to sequester more carbon, with less disturbance, so no-till or minimal till, those sorts of sustainable practices. That’s important for a long-term view of land stewardship, which again has been a hallmark of the good food movement, in stark contrast to a really commodified, centralized agricultural system that has prioritized profits, efficiency, and scale over land stewardship. Obviously, as we are facing a climate crisis, we must be able to sequester more carbon in the soil, build resilient systems that will weather the extreme weather events we’re experiencing, and maintain a much longer-term view than short-term returns.

I often get asked if those kinds of systems can feed the world, and I feel that we could do a lot better than what we are doing with a global commodified center. We’re seeing the effects of that system right now in terms of the conflict in Ukraine, the effect that’s having on grain, which is an example of a global commodified market. One of our programs here in Glynwood is to foster regional grain production in the Northeast. If we all had regional food systems that were resilient and regenerative, we would stand a better chance of feeding ourselves rather than a very centralized system that is vulnerable to physical, cultural, sociopolitical struggles.

Glynwood is training young farmers through apprentice programs to be able to address issues locally and have them understand how it connects to the bigger picture. However, when I last visited Glynwood, I didn’t see any beekeeping. Isn’t Glynwood active in bee conservation?

We have had bees in the past, and we actually have an apprentice who’s been trying to catch a swarm this season. I don’t think there are bees residing right now, but she’s keenly interested in beekeeping. So, at the moment, Glynwood doesn’t have bees because our beekeeper moved on to another area. But many of the farms that are in our programs throughout the Hudson Valley have apiaries and integrate beekeeping into their systems. We just happen to be in between beekeepers, while there is an emerging beekeeper who is in need of bees.

So, that’s part of the picture?

Yes, of course.

But certainly, it has to be.

We’re blessed here physically at Glynwood . As you’ve seen, we are surrounded by tens of thousands of acres of protected land. So there’s a lot of biodiversity and pollinators that are just naturally here. So that’s also wonderful for this property in particular.

I think one of the biggest attributes of regenerative agriculture is that it prioritizes soil health and microbiology. Soil microbes are all-important in fixing nitrogen and unlocking phosphorus. Glynwood is doing a wonderful job of training young farmers in this type of regenerative soil maintenance. Are the benefits of this food production system something that you can pass on to small backyard framers?

Sure. We monitor our soil through simple soil tests that are available through Cornell in New York, for example. Yale also has a program. A lay gardener can find ways to learn about their soil and then have it monitored easily. In the past, we have done workshops and soil health field days in soil management for the general public, and we teach about soil stewardship. But we certainly do in our farmer training, —and region-wide—not just for the farmers locally. There’s been a wonderful collaboration emerging in the Hudson Valley dedicated to educating folks about soil science, mostly professionals, not necessarily lay folks. But I think there are many other programs and resources. One being Dr. Masoud Hashemi’s of Umass-Stockbridge School of Agriculture, who is one of the leaders in the field of soil health and microbial activity and has instructed us here.

What other organizations working in health, food, and the environment do you admire, and why?

UC Santa Cruz, my alma mater, is one. They have an excellent farmer training program where students are resident on the farm for a year, and the curriculum is really solid. I also really admire what they’re doing in terms of formal curriculum around farming– such as food sovereignty and food justice. 

I’m a great admirer of Soul Fire Farm in Petersburg, New York, that’s educating Black farmers specifically and really thinking about food justice and food sovereignty. Quivira Coalition, based in Santa Fe, New Mexico, is another organization building food justice capacity. They provide farmer-rancher training and sharing of information, ideas, and resources with the general public. Intervale Center is a Vermont-based incubator program that we’ve learned a lot from over the years. The program gives land access to new entry farmers in a collective, cooperative way. I think they are doing a great job. There aren’t many organizations that are centering on regional food. Glynwood is really unique in that way. But there are organizations like the ones I mentioned, that are either addressing farmer training or food sovereignty. An international organization that I like quite a bit is called A Growing Culture that is working globally on serving smallholder farmers who are mostly women, and they’re doing that very thoughtfully. 

Well, what are you most proud of with Glynwood’s efforts?

I wouldn’t have Glynwood take all the credit for this, but I am very proud of how we have changed or helped evolve the narrative of good food away from an elitist foodie perspective and more towards a food sovereignty perspective. I think if we rewind 10 years ago when I started here, it was sort of bougie. The good food movement was primarily catering to wealthy privileged folks and featured white tablecloth restaurants and four-hour meals, and that sort of business. And that’s not what I’m interested in, and I think it’s taken time for folks to understand that high-quality consciously grown or raised food should serve all of us and not just the very few.

This has increasingly shown up in our programming here at Glynwood, but beyond that, the conversation is evolving toward food as a human right and as a social justice issue, rather than just joyful, flavorful stuff, which is of course why it’s so great. But it’s really moved beyond that, and I’m proud of Glynwood’s role in the evolution of that perspective.

That is very important. And I feel like you’re somebody who clearly has their finger on the pulse of the Hudson Valley region, but also nationally and internationally, because we’re all facing very similar problems around the world. And I’m wondering who the thinkers and the writers are that have been major influencers on you and your thinking.

There are so many. Joan Gussow, Alice Waters, and Mary Cleaver are three women that come to mind that were early influences on my thinking. Fred Kirschenmann is also really important. I encountered them, and Frances Moore Lappé, the author of Diet for a Small Planet, early in my interaction with the food movement. 

Lately, I’ve been really impressed with my partner’s podcast Food with Mark Bittman. He highlights awesome writers and thinkers, such as Leah Penniman, the co-founder of Soul Fire Farm. Her book Farming While Black was really eye-opening and important for me. So was Marya Rupa and Raj Patel’s most recent book, Inflamed: Deep Medicine and the Anatomy of Injustice.Laura Lengnick, who’s our director of agriculture, also recently published a second edition of her book, Resilient Agriculture: Cultivating Food Systems for a Changing Climate.

Are there things individuals can do to help the regenerative agriculture movement?

There’s nothing better than planting your own seeds and serving the food you have grown to the people you love a few months later. I totally encourage folks to do that if they can. It does take some time and some of us don’t have that privilege of time available. I would say to those folks that one of the best ways you can support your regional farmers, have fun, and improve your health is by joining a community-supported agriculture farm, that’s a CSA farm.

According to that model, you typically pay upfront for a season’s worth of food, and you pick up your weekly share as an investor in that farm. I grow some food, but I also participate in our CSA, and it’s synergistic because I’m able to ask the farmers questions about who’s eating my basil and such. When I’m struggling with my garden, it’s great to be able to get professional answers. Some CSAs offer educational activities for their members.

CSAs are good for the farmers and so good for the eaters in terms of health outcomes.

Learn more: Recommendations from Kathleen Finlay:
Food by Mark Bittman (podcast)
Healing Grounds by Liz Carlisle (book)
Resilient Agriculture by Laura Lengnick (book)
Animal, Vegetable, Junk by Mark Bittman (book)
The Edible Magazines
Heritage Radio (several podcasts)

Kathleen Finlay is a leader in the regenerative agriculture movement. She has been President of the nonprofit organization The Glynwood Center for Regional Food since 2012. Previously, Kathleen was a Director of Harvard’s Center for Health and the Global Environment. She is also the founder of Pleiades Network, a membership organization working to advance women’s leadership in the sustainability movement.

This article offers a glance into the olfactory world of nature, in which we first discuss nature and its odors, then describe the scents that these odors produce. The difference between odors and smells is that odors are molecules in the air and smells are the mental representations of these odors in our minds. That there is an (often ignored) distinction between these two concepts can be a little confusing, because in color perception, we use the same word for both concepts. The term “color” refers to both the physical pigments in the environment and how they appear to us mentally. In comparison, the olfactory world is much more complex.

Part I: Nature and Its Odors

Most odors are generated by living things: plants, animals, and microorganisms. Some nonliving things also produce odors. Ozone and formaldehyde are formed by atmospheric processes, and hydrogen sulfide is produced by volcanoes, but essentially, the world was odorless before living things came along and started producing a wide variety of different odorous molecules. Roses alone release more than 250 different molecules. These molecules contribute in complex ways to the rose smell. Many of them contribute very little, while the mixture of beta-damascone, beta-damascenone, and (-)-cis-rose oxide, which combined make up less than 1% of the total volume of rose essential oil, is necessary for the rose’s characteristic scent.

The complexity of the possible mixtures of odor molecules is staggering. There are over 30 billion odorous molecules and around 2 million of them have so far been found in nature. 

A common misconception, dating back to Aristotle’s writing on scent, is that odor molecules are components of their source objects and detach to become airborne, like water molecules evaporating from a lake. In reality, rose odor molecules are actively produced in certain parts of the plant, transported to other structures where they are stored, and then released in appropriate situations. Enzymes that have evolved specifically for this activity make it feasible for this energy-intensive process to occur. A rose does not have an odor, it makes an odor. And it does make that odor for a reason. It performs an adaptive function for the rose rather than being a byproduct of being a rose.

Odors as Signals

A well-known function of flower odors is to attract pollinators. The odor is a signal the flowers send to potential pollinators, usually insects. But pollinators are not the only recipients of plants’ odor signals. Some plants also use odors to signal to other plants. Black Walnut (Juglans nigra) gives off a molecule called juglone that repels other plants, thereby reducing competition for space, water and nutrients. Other trees, such as sugar maples, sycamore, and red oak also produce allelochemicals to assure their survival. When grass gets damaged, it releases molecules that elicit the typical “cut-grass” smell. These molecules are signals for other grass that the plant is under attack. In animals, it would be called an alarm pheromone. 

Potential predators are also common recipients for plants’ odor signals. For example, caraway seeds make the chemical carvone that gives them their distinct scent in order to repel insects and other potential animals which may eat them. Ironically, humans like the flavor of caraway and producing carvone has increased caraway’s danger of being eaten by people. The same dynamic is known for the molecules that give chili peppers their spiciness. Their function is to deter animals from eating them, but humans have developed a masochistic liking for the taste and started eating chili peppers.

When a plant or animal dies, bacteria break down the large, synthesized odor molecules into smaller ones. These smaller molecules are responsible for the smell of decay or fermentation. They do not have a function but are a byproduct of the bacteria breaking down larger molecules. Plants may then use the small molecules produced by bacteria again to make larger molecules and complete the cycle. 

Citrus Fruits

Different plants create various odor molecules, and as a result, they all have a distinct smell. However, sometimes plants have similar smells because they produce similar mixtures of molecules. The fruits of citrus plants are a well-understood case study for the contribution of odors to smells. All the citrus fruits available in a supermarket—oranges, limes, lemons, grapefruits—are the result of humans crossing the four naturally-occurring citrus fruits: pomelos, true mandarins, citrons, and small-flowered papedas. For generations, farmers have hybridized these species to generate hundreds of new variants that combine the characteristics of the four ancestral citrus fruits. The cross between a pomelo and a mandarin, for example, results in a sweet orange, and if a sweet orange is crossed again with a pomelo, the result is a grapefruit. In this area defined by the ancestral species, fruits may be moved within this spectrum. These ancestral species produce different odors because they evolved different odor-producing enzymes. As the plants are hybridized, these enzymes can be combined in novel ways, thereby changing what odor molecules are being produced. The scents of various citrus fruit varieties differ as a result of the recombination of odor synthesis pathways. All citrus fruits share many of the odorous molecules that they release. For example, limonene, a molecule with a citrusy, fruity smell, makes up more than 50% of the essential oils of most citrus fruits.

Common elements like limonene are responsible for the olfactory qualities that are shared by all varieties of citrus fruits. But of course, not all citrus fruits have the same smell, it is generally easy to distinguish the smell of an orange from the smell of a grapefruit. These differences in the odor of citrus fruit varieties are due to molecules in the mixture that are only found (at relevant concentrations) in those specific kinds. The molecule nootkatone, for example, is only found in grapefruit, and it is responsible for the characteristic bitter aroma of grapefruits. The combination of shared and exclusive odor molecules explains the similar yet unique smells of citrus fruits.

Orchids

All citrus fruits are closely related, but there are also cases of widely different plants which produce the same odors. These are examples of convergent evolution, which happens when unrelated species independently evolve the same solution to a problem. The textbook example is the independent evolution of wings for flying in bats, birds, and insects. When it comes to plants, orchids are well known for producing a wide variety of odors that often mimic those of other plants. There are orchid species that smell like piña colada, white chocolate, vanilla, strawberry, or rhubarb. These orchid species have evolved ways of synthesizing the same molecules, and hence comparable scents of other unrelated plant species.

Not all orchids mimic the smell of other plants. Some orchids smell like rotting flesh to attract pollinating insects that usually eat decaying meat. Others attract bugs by feigning to be a female who is available and emitting an odor similar to the pheromones of insects. Orchids are masters of mimicking smells found in the natural world and using them for the purpose of getting pollinated. There is a type of orchid in Korea that mimics the alarm pheromone of bees, which attracts insects that prey on bees. The predatory insects smell what they think is an injured bee and, searching for the easy prey, get trapped in the orchid and pollinate it.

Part II: Smelling Nature

For an odor to elicit a smell, it has to be smelled by somebody. This happens when the odor molecules emitted by plants reach our nose. On the very top of the nostrils, between the eyes, the olfactory nerve enters the nasal cavity where it terminates in the olfactory epithelium. The olfactory nerve consists of different types of sensory neurons. Each type expresses one of hundreds of different odorant receptors, which are the molecules that bind to odor molecules. The neurons of the olfactory nerve, which are directly exposed to the unfavorable environment of the nasal cavity, continuously die and regrow. 

Combinatorial Code

In our nasal cavities and the air surrounding us, various combinations of odorous airborne molecules are present at any one time. Different molecules from this mixture bind to various odorant receptors, thereby activating the sensory neuron. The sensory neuron then sends a signal up the olfactory nerve, through the skull, into a brain structure called the olfactory bulb. The olfactory bulb consists of spherical structures called glomeruli. In each glomerulus, sensory neurons of the same type converge. Every molecule will activate a combination of receptors. To give a hypothetical example, vanillin may activate receptors 73, 115 and 299, the activation of the receptor combination 73, 115, 299 therefore signals to the brain that vanillin molecules are being encountered. This is known as the “combinatorial code” of olfaction: each type of odor molecule activates several receptors, and each receptor is activated by several types of odor molecules, resulting in a unique combination of activated receptors for each type of odor molecule.

Odorant Receptors

The odorant receptor gene family is the largest in our genome. Humans have, depending on the counting method, 400 or 800 odorant receptor genes, compared to only three-color pigments. Whether we count 400 or 800 odorant receptor genes depends on whether pseudogenes are counted. Pseudogenes are genes that have accumulated mutations that rendered them non-functional. When scientists first sequenced the human genome and realized that half of our odorant receptor genes are pseudogenes, they speculated that this was a consequence of the declined importance of olfaction for our species. If our sense of smell no longer plays a role in our survival and reproductive fitness, there is no selective pressure against deleterious mutations in odorant receptor genes and these mutations can accumulate, turning the genes into pseudogenes. However, after the genomes of various other animal species had been sequenced, it became clear that odorant receptor pseudogenes are very common in almost all species, including those well-known to rely heavily on their sense of smell.

Specific Anosmias

Many odorant receptor genes are found as a functional variant in some people and as a non-functional variant in others. In these cases, some of us carry the gene while others carry the pseudogene. People who carry the non-functional variant sometimes have reduced sensitivity to the odor molecules the receptor binds. This is a condition known as “specific anosmia” or “partial smell blindness.” Somebody with specific anosmia has a normal sense of smell except that they cannot smell a specific group of molecules or smells, such as musk. Specific anosmia is the olfactory version of partial color blindness (such as red-green color blindness), which is also caused by genetic variation in the gene for the protein interacting with the stimulus. However, there is a conceptually very important difference between specific anosmia and color blindness: in color perception, over 90% of the population have functionally the same set of photoreceptors. In olfaction, everyone has a unique collection of odor receptors, with the exception of identical twins. There is no “normal” set of receptors and therefore also no standard way of perceiving odors. As a result, an odor does not have a smell. Instead, a smell is assigned to an odor, and which smell somebody assigns to a specific odor depends on which set of receptors they are smelling it with. If two people assign different smells to the same odor, there is no principled way of determining who is right. Because they can both be right.

We don’t normally recognize that we have a specific anosmia because almost all odors we encounter are mixtures and when we are less sensitive to a component of the mixture, we are still able to smell it. Differences in the perception of the aroma of cilantro, and inability to smell the characteristic odor of urine after eating asparagus, are two examples of a specific anosmia that has noticeable effects on perception and behavior in everyday life. Another example is the specific anosmia to the odorous steroid androstenone and related components. These components, which are odorless for many, but have an unpleasant smell of sweat and urine for most, are found in the meat of uncastrated male pigs. People with this specific anosmia are less likely to detect a taint in such meat and are therefore more likely to eat it.

Influence of Background Beliefs

How we perceive a given odor through our sense of smell depends strongly on our odorant receptor variants. How we judge odors on the other hand is deeply affected by the context and our previous experiences. The various reactions people have to certain odors provide insight into how deeply these aspects might influence opinions—like pork, fermented food, and spices like garlic—or cigarette smoke in different populations.

The influence on background beliefs on olfactory judgments has been confirmed in controlled studies. In one of those studies, subjects were asked to rate the smell of isovaleric acid, a molecule that is found both in the odor of parmesan cheese and dirty gym socks because it is produced by bacteria that thrive in both environments. (The artist Sissel Tolaas once isolated bacteria from David Beckham’s dirty gym socks and used them to make cheese.) For the study, one group of the subjects who were judging the smell of isovaleric acid were under the impression that the source of the molecule was sweat, while another group was under the impression that the source was cheese. Depending on what they believed to be the source of the odor (the real source was a chemical factory in which the isovaleric acid was synthesized), subjects assigned dramatically different pleasantness ratings to the odor.

Influence of Other Modalities

In another study that demonstrates the tremendous impact of non-olfactory factors on peoples’ judgments of odors, researchers used students of wine making at a school in Bordeaux as their subjects. These wine experts were asked to smell (but not taste) three different wines and describe their aroma by picking descriptors from a list. One wine was a red wine, the other a white wine, and the third the same white wine but colored red with odorless food coloring. The subjects’ description of the odor of the white wine with the red coloring was much more similar to the description of the odor of the red wine than to the description of the odor of the white wine. This means that a wine’s description of its aroma was influenced more by its color than by its smell.

While the results of these experiments are clear and dramatic, the interpretation of the results is difficult. Does the white wine actually smell different when it is colored red, or does it smell the same but the smell is judged differently? I believe the latter is the case. The students knew which descriptors are commonly used for red wines: tar, leather, plum, cherry—and which descriptors are commonly used for white wines: honey, apricot, apple, hay. They did not want to look foolish by using white wine descriptors to describe a red wine. Their background knowledge, rather than helping them with the task, was entrenched enough to overrule the sensory evidence. Designing an experiment that would confirm or refute this interpretation of the result is challenging, though.

Influence of Previous Experiences

The studies with the isovaleric acid with various labels and the wine with different colors show the impact of background beliefs and sensory input from other modalities on accounts of olfactory perception. In addition, these reports are shaped by previous experiences with the smell. The pleasantness of a smell associated with a food or drink that has caused food poisoning, for example, will be judged very differently before and after it caused the discomfort. These effects can be astonishingly long-lasting and difficult to overcome. Even scent experiences in the womb, before being born, impact lifelong attitudes towards the experienced odors. Researchers in France demonstrated this by recruiting pregnant women and dividing them into two groups. One group was instructed to regularly eat anise-flavored candy throughout their pregnancy, whereas the other group was instructed to avoid such candy. When the newborns, minutes after they were born, were tested for their response to anise odor, they demonstrated the predicted differences between the two groups. Babies of women who consumed anise-flavored candy during pregnancy displayed attraction and curiosity towards the odor whereas babies in the other group were indifferent to the scent.

This short glimpse into the world of odors and smells shows that the odors in nature, the mental representations elicited by them, and the verbal reports about the odors are more complex and multilayered than we usually appreciate. The smells of nature, especially those that are in danger of disappearing, are deserving of our respect and appreciation and we must ensure that they can be experienced by future generations.

Dr. Andreas Keller received his PhD in Genetics from the Julius-Maximilian-University in Wuerzburg, Germany, and holds a second PhD in Philosophy from the City University of New York. He continues research in olfaction at Rockefeller University and is the founder and owner of the NYC art gallery Olfactory Art Keller.

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