Pollen: Strong Reactions

I have a love-hate relationship with pollen. It’s been that way most of my life.

I love pollen because of its crucial role in propagating a vast array of plants, including many of the fruits, nuts and grains we rely upon for food. Plus, lots of pollen is produced by the beautiful forest trees and wildflowers I so enjoy, ensuring the seeds of the next generation.

I hate pollen because I’m allergic to most types, and once, in an indirect way, pollen tried to kill me.

A week ago, while running with my dogs in the forest, I noticed my breathing was more difficult than usual on an uphill stretch. It felt as though I couldn’t catch a full breath. I even coughed lightly a couple times. Oh no; the virus? I wondered, then quickly dismissed the idea, as I otherwise felt great.

The next morning, walking through the forest after a night of heavy rain, I noticed patterns of bright yellow pollen on the dirt where the rain had created rivulets down the forest road, taking the pollen along with it.

dirt road with pollen
Yellow grass and tree pollen left on top of the dirt of a forest road after a night of rain. June 9, 2020.

A few days later, while enjoying the evening with a magazine and glass of wine on my deck, I noticed a coat of yellow pollen on my glass deck table.

pollen on glass table
Glass-topped deck table with a couple days worth of yellow pollen grains blown there by the breeze. June 12, 2020.

I’m surrounded by field grass and forest trees. No wonder I was noticing a change to my breathing while running: allergies.

Sensing another natural world blog post, I did some rudimentary research which took me down yet another deep rabbit hole of science and personal anecdotes. The research is shared below in italics (with editing for brevity and clarity), and my own thoughts, experiences and memories in roman (normal) type. I hope you don’t sneeze as you read.

bee,  pollen
Diadasia Bee Straddles Cactus Flower Carpels; Jessie Eastland, CC BY-SA 4.0

What is Pollen?

Individual pollen grains are small enough to require magnification to see detail.

I can attest, however, that when one or more pollen grains find their way under your contact lens, they feel as large as boulders grains of sand. Painful.

Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower.

Bees, flies, spiders, mites, beetles (including some Ladybird/ladybug types), bugs such as flower bugs, cicadas, planthoppers, aphids and other insects feed on pollen. Some species of Heliconius butterflies (colorful butterflies known as longwings) consume pollen as adults, which appears to be a valuable nutrient source, and these species are more distasteful to predators than the non-pollen consuming species.

Although bats, butterflies and hummingbirds are not pollen eaters per se, their consumption of nectar in flowers is an important aspect of the pollination process.

Bee pollen for human consumption is marketed as a food ingredient and as a dietary supplement. The U.S. Food and Drug Administration (FDA) has not found any harmful effects of bee pollen consumption, except from the usual allergies.


The transfer of pollen grains to the female reproductive structure is called pollination. This transfer can be mediated by the wind, in which case the plant is described as anemophilous (literally wind-loving). Anemophilous plants typically produce great quantities of very lightweight pollen grains. Non-flowering seed plants (e.g., pine trees) are characteristically anemophilous. Anemophilous flowering plants generally have inconspicuous flowers.

Entomophilous (literally insect-loving) plants produce pollen that is relatively heavy, sticky and protein-rich, for dispersal by insect pollinators attracted to their flowers. Many insects and some mites are specialized to feed on pollen, and are called palynivores.

Pollen.com offers a pollen map to help assess pollen levels throughout the U.S.

Pollen Allergies

Most allergies referred to as “hay fever” are caused by pollen, pet dander, dust particles, and mold spores. The name comes from the most common seasonal allergen, grass.

When I was thirteen, still relatively new to allergies, I didn’t understand why springtime allergies were referred to as hay fever. I occasionally got to ride horses at a nearby farm where you could pay to ride by the hour, and from what I could see from those experiences, “hay” was just light brown straw bundled into bales and stored in the barn. I didn’t realize that fields full of tall grass were mowed, the grass then baled to feed the horses later and called hay. (Be kind; I was only 13 and a city girl.) Then one time my friend and I were riding at the farm and a storm came through, with lightning, thunder and rain. We dashed back to the barn early where we had to wait 30 minutes for my father to pick us up at the usual time. Naturally, we sat on hay bales as we waited, and before long my nose started running, my eyes itched, and I began sneezing – my worst allergic reaction to date. It became so bad that I went outside and stood shivering under an eave until my father arrived. When I told him what happened, wondering if I was allergic to the horses, he assured me it was the hay, that I was allergic to the grass pollen that must have remained even after bundling the grass into bales.

According to the American Academy of Allergy Asthma and Immunology: A number of different allergens are responsible for allergic reactions. The most common include pollen, dust, food, insect stings, animal dander, mold, medications/drugs, and latex.

Weather conditions affect pollen levels. Wind and humidity may affect pollen counts. Because pollen are small, light and dry, they are easily spread by wind, often over long distances. When it rains or is humid, pollen becomes damp and heavy with moisture, keeping it more still and closer to the ground.

Pollen from plants with bright flowers, such as roses, usually do not trigger allergies. Pollen from trees, grasses and low-growing weeds is small, light, and dry, well-suited for dissemination by wind, triggering allergies.

An allergy to at least one type of pollen – called pollinosis – is fairly common. Between 10 to 30 percent of adults in the U. S. experience hay fever, nothing to sneeze at (sorry).

Allergy Treatments

Antihistamines are effective at treating mild cases of pollinosis.

When my own hay fever first became noticeable, when I was about ten, I tried to tell my mother what I thought was wrong. Another student at my elementary school had allergies and after hearing him describe his symptoms, I was sure I did, too. Mom didn’t believe me. (I would learn much, much later than as a narcissist lacking empathy, if my mother hadn’t experienced something herself, she didn’t believe I was experiencing it.) My father did, though, so I was seen by our pediatrician, who decided to do skin prick testing. The nurse made a series of small scratches down my back, three columns, each with several rows. On each scratch they put a drop of a type of allergen, very diluted, and waited to see if my skin reacted. To everyone’s surprise (but mine), I tested positive (my skin reacted) to most of the usual suspects: grasses and tree pollens, but also dog and cat dander, dust and molds. The only good part of those results from my perspective was my mother’s embarrassment at not initially believing me.

Chlor-Trimeton was the antihistamine prescribed by doctors back then, really the only option. But the drug knocked me out; made me extremely drowsy so I could only take it at night and even then, I didn’t like the grogginess and brain fog that lingered the next day so I quit taking it except for the worst reactions. I just sneezed and dripped my way through the hay fever season. We had a dog and a cat at the time, and no way was I going to complain about being allergic to them. They continued to sleep on my bed. Allergies just became part of my life, something to learn to ignore as much as possible. They didn’t slow me down much.

In 1993, when I was in my mid-30s, loratadine (Claritin) came out as a prescription medicine. My doctor prescribed it. I had much less drowsiness and I was able to control most of my symptoms without feeling groggy, although I was still careful what time of day I took it. It was expensive, something like $80/month, but thankfully my insurance covered it. Eventually, the patent on Claritin expired (in 2002) and generic loratadine became over-the-counter and affordable. Since then I’ve taken a 10 mg loratadine pill every night, even in winter because I still have the pet dander and dust allergies to contend with. I can get a year’s supply for about $14. I still sneeze some, and every spring for a few weeks when the pine and fir trees are dropping pollen in the forest my lungs feel thick and heavy when I run, as if I can’t get a full breath, but loratadine keeps the worst of my symptoms at bay.

Decongestants can be administered, as tablets and nasal sprays.

Decongestants also made me drowsy, and some made me jittery. Since a stuffy nose was the least of my symptoms, I stuck with the antihistamines which do a better job of addressing my symptoms of sneezing, itchy/watery eyes and tickly throat.

Allergy immunotherapy treatment involves administering doses of allergens to accustom the body to pollen, thereby inducing specific long-term tolerance. Allergy immunotherapy can be administered orally (as sublingual tablets or sublingual drops), or by injections under the skin (subcutaneous). Discovered by Leonard Noon and John Freeman in 1911, allergy immunotherapy represents the only causative treatment for respiratory allergies.

In 2003, after an especially rough spring when my breathing felt compromised whenever I ran uphill, I decided to try allergy immunotherapy. (Allergy immunotherapy only works for pollen allergies, not food or insect sting allergies.) Again, I was lucky enough to have insurance that would cover all but small co-pays for the treatment, and I trusted my allergist when he said it was effective.

To best know what allergens to include in the therapy, I first underwent another round of testing. This time, they injected small bits of allergens under my skin, rather than scratching and dropping the allergen onto the skin. Once again, I reacted to all the usual suspects – a wide array of grasses, trees and weeds, so many that I joked that if it pollinates, I’m allergic to it.

Since I was undergoing pollen testing, my allergist recommended testing for a few common food and other allergens. Honeybee sting caused a severe reaction. Dog and cat dander were lesser allergens, as was dust. Mold was bad; I was told to make sure there wasn’t any in my home.

Some foods were also tested. At age 20 I learned that I was allergic to milk, but otherwise I didn’t expect any reactions to foods. I did react fairly strongly to dairy products and my allergist advised me to avoid milk, cheese and ice cream. (No ice cream? What? Actually, I found I enjoy sorbet almost as much.)

The big shocker was an allergy to shellfish, a reaction so strong that my allergist said I should always carry an Epipen and be very careful in restaurants, informing staff of my allergy when ordering so that there wouldn’t be any cross-contamination of my food as it was prepared in the kitchen. I was completely surprised, as I’d grown up eating – and loving – shrimp and prawns, and crab dip was a holiday gathering staple in my family. I admit, being skeptical, a few months later I decided to take just one tiny bite of a prawn at a holiday dinner gathering. Almost immediately, my lips and tongue started to tingle. Thankfully that’s as far as my reaction went. I understood then why my allergist was so stern in his warning. I’ve never tested that allergy again.

I soon began immunotherapy for my pollen allergies. I would visit an outpatient clinic where a nurse would inject my special recipe of allergens (all in diluted amounts, mixed together, the strength a little stronger each visit) into my upper arm, then instruct me to sit and wait for 20 minutes in the reception area. She would then check the injection site, which was invariably red, measure the size of the red circle with a special card and record it in my chart. Sometimes the red circle was dime-sized, other times almost quarter-sized (not good).

I don’t remember how frequently these visits occurred; I think they started out once per week, then twice per week as I progressed, but the entire process was at least three months. The goal was a once monthly maintenance shot, or better yet, a once-or-twice-per-year injection to manage symptoms.

Everything went fine until my last appointment.

I got my shot, sat down to read, had the nurse check the injection site, which was larger and itchier than ever before, and was told I could leave. But I stayed another ten minutes; something didn’t feel right and the reaction at the injection was bigger than ever. Eventually I left and started the 15-minute drive home. About five minutes into that drive, on the freeway, the back of my throat started tickling, then my tongue. I felt my throat tightening, my tongue swelling. This was before I had a cell phone, so I had to decide: turn around and return to the clinic, or go home. It was near closing time at the clinic when I left; they might not be open by the time I got turned around and back there. I went home.

I wasn’t feeling any worse when I walked in the door, greeted by my dogs, but I immediately called the nurse at the clinic to report my symptoms since they’d always stressed to do so if anything unusual happened. She told me to hang up and immediately call 911, to tell them I’m having an anaphylactic reaction and that I needed a shot of epinephrine immediately.

That got my attention. Still, I didn’t think I was having an anaphylactic reaction. I vaguely knew that anaphylaxis meant my airway could be completely obstructed due to swelling, killing me. If I was experiencing an anaphylactic reaction, it wasn’t getting any worse and I was able to breathe, but since I’d never had one to judge by, I figured the nurse knew more than me and did as she instructed.

The 911 dispatcher took my information, said a Medic unit was on its way, and told me to unlock my door and go lie on my bed until they arrived. “Stay as calm as possible,” she said before hanging up.

Seriously? Whoa. This must be serious. My heart rate went up a bit.

I made sure my door was unlocked and went to lie down. My dogs followed me into the bedroom. Almost immediately after getting prone on my bed, my breathing became more difficult, my throat tighter. My dogs became concerned, my raspy breathing sounded so different. They wouldn’t leave the side of my bed; they pressed their noses against my arm. I ran my fingers through their thick fur to calm myself while I wondered if this was how I would die. After that bizarre thought trickled through my brain, I got pissed, sat up, and decided I refused to die without a fight.

Sitting up immediately improved my ability to breathe.

My next thought was that the Medics would miss my driveway. It was on a curve, on a hill, and easy to drive past. If I got worse and every second counted, their getting lost could be tragic. I went outside and stood at the bottom of my driveway so I could flag them down when they came. After a few minutes I heard the siren. When they came around the curve, I waved them up my driveway.

They thought I was a family member. They expected their patient to be prone, in the house. Once I assured them I was indeed the patient they followed me inside. I explained the short history of my situation, emphasizing that I felt better standing up or sitting, that my symptoms were already subsiding, my throat less constricted and my breathing easier. They took my blood pressure, pulse, listened to my lungs, etc. I also told them that the clinic nurse said I needed an epinephrine injection. Twice, I mentioned that.

Turns out Medics weren’t allowed to give epi shots at that time.

They refused to just leave me alone, though, even though I assured them I was better. I wasn’t distressed in the least by this point, quite calm, actually. I was steadily improving. Still, they insisted on calling an ambulance that would transport me to a hospital ER where I could be evaluated.

At the time I didn’t think to refuse. I should have, because it took time for the ambulance to arrive, the Medics waiting all the while, and more time for the ambulance to drive me all the way into downtown Seattle to an ER, and then, after sitting several minutes in the ER waiting to be seen – my symptoms almost completely gone by this time – the doctor simply gave me a Benadryl pill and released me to go home.

A Benadryl!

The ambulance ride cost me $400 (that was my co-pay). I don’t remember how much the ER visit was because my insurance covered most of it, but I likely had a co-pay of about a $100.

Damn expensive Benadryl pill.

Valuable lessons learned, though. I now take pollen, shellfish, and bees seriously, as any one of them could kill me if I’m not careful. I ALWAYS have Benadryl nearby, in my running pack, in my car, in my home and when I go on vacation. It’s effective, and way cheaper than an ambulance ride to the ER.

Scotch Broom: The Pollinating Plant I Hate the Most but also Love for a Memory it Sparks

Hate is a strong emotion. Toward a plant? Weeds are annoying, sure, but I don’t hate them. They’re just trying to survive, like the rest of us. Figuring they must have some purpose I’m not aware of, I’ll pull them from my wildflower garden and driveway, but I leave them alone in my lawn, and I won’t put toxic chemicals on them regardless of where they appear.

Growing up near Seattle, I used to think Scotch broom was a pretty evergreen bush covered with bright yellow flowers much of the spring and early summer. In western Washington it was often planted alongside freeways and highways to beautify medians. It grows three to six feet tall and quickly takes over any area it’s planted, out-competing native plants.

Scotch broom growing alonside a freeway. Photo courtesy Washington State Noxious Weed Control Board.

But as I became more aware of my seasonal allergies, and after I started driving, I realized that in summer, driving with the windows down (no A/C in our cars back then) along a stretch of freeway with Scotch broom blooming on both sides, my nose would tickle and I would sneeze. I put two and two together, and I was right: Scotch broom triggers seasonal allergies in lots of people. It actually made me drowsy as I drove if I had to breathe in its pollen for very long. I began to loathe the plant, and now, just the smell of Scotch broom flowers makes me retch, the association with allergies so strong.

According to National Park Service Scotch broom is an “exotic” species: Scotch broom (Cytisus scoparius) is found along the east and west coasts of North America and in Idaho, Montana, and Utah. Native to northern Africa and parts of Europe, it was first introduced to North America on the east coast and was later introduced to California as an ornamental. From the 1850s through the early 1900s, Scotch broom was frequently planted in gardens. Later, it was used for erosion control along highway cuts and fills.

In 1988 – when I was 32 years old – Scotch broom was listed as a noxious weed in Washington. One could no longer buy, sell or transport the plant or seeds in or out of the state. Finally! The fact that so many had allergies to it was also acknowledged, that it could be dangerous for certain drivers. Scotch broom started disappearing from freeway landscapes, but not easily or quickly; it had to be hit with herbicides, or cut in late summer when dry. I imagine the eradication process was a hit to state and federal road budgets. It took years before I no longer smelled Scotch broom while driving certain stretches of freeway around Seattle.

Scotch broom is classified as a noxious invasive species in California, Oregon, Washington, British Columbia and parts of the east coast of North America, as well as Australia, New Zealand and India.

In days gone by, broom was considered a sign of plenty when it bore many flowers. It was used in a decorated bundle at weddings if rosemary was scarce.

Its strong smell was said to be able to tame wild horses and dogs.

In Italy, the shrub was burnt to stop witches.

The name of the House of Plantagenet, rulers of England in the Middle Ages, may have been derived from common broom, which was then known as planta genista in Latin. The plant was used as a heraldic badge by Geoffrey V of Anjou and five other Plantagenet kings of England as a royal emblem. The “broomscod”, or seed-pod, was the personal emblem of Charles VI of France.

Apparently the Plantagenets didn’t suffer from seasonal allergies.

Ironically, Scotch broom features is one of my treasured memories of my father.

A few years after my parents divorced, my father bought a house. The summer between undergraduate college and law school, I lived with him in that house. One spring day, sitting on the deck, I noticed the smell of Scotch broom. Curious of the origin, we discovered a couple of shrubs growing under the deck, alongside the house.

A Scotch broom bush about the size of the ones growing under my father’s deck. Photo: Anne Tanne, National Park Service.

The next day I came home to find my father attacking those Scotch brooms, cutting them back and then digging out the roots to remove all evidence of their existence. He surveyed the rest of the property to make sure there weren’t any others lurking nearby.

I didn’t ask him to do that. He simply took it upon himself to make sure I was comfortable by removing something I was allergic to. Such a simple yet profound act of caring. He never questioned my allergies, like my mother had. It was one of those moments when, without a word spoken, he showed me how much he loved me, similar to all the times when, after we hugged goodbye at the end of a visit, I would get in my car to drive home and after starting the engine, Dad would wipe my headlights clean to make sure I had the best possible visibility in the dark.

Simple acts of kindness and love that turned into enduring memories.

So, What is Pollen Good For?

Besides keeping plants reproducing and bees and butterflies busy? Turns out pollen tells stories of historic, environmental and legal value to us humans.

The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics.

Palynology is used by geologists to help date rocks for petroleum, mining, and water exploration and to help unravel the history of plants on Earth. It’s used by geographers to investigate climatic and environmental change; by botanists for plant taxonomy and phylogeny; by immunologists to investigate allergenic pollen; by archaeologists to study the customs, rituals and agricultural practices of ancient peoples; by zoologists and environmental scientists to understand foraging habits of insects, birds and mammals, and to investigate past native vegetation and habitats in order to preserve the present and protect endangered species.

In forensic biology, pollen can tell a lot about where a person or object has been, because regions of the world, or even more particular locations such a certain set of bushes, will have a distinctive collection of pollen species. Pollen evidence can also reveal the season in which a particular object picked up the pollen. Pollen has been used to trace activity at mass graves in Bosnia, catch a burglar who brushed against a Hypericum bush during a crime, and has even been proposed as an additive for bullets to enable tracking them.

If I were an author of crime fiction, I would definitely include pollen as one of my clues, my forensic palynologist protagonist loving and hating it simultaneously.

Feature image: Scanning electron microscope image (500x magnification) of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), prairie hollyhock (Sidalcea malviflora’’), oriental lily (Lilium auratum), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis).

16 thoughts on “Pollen: Strong Reactions”

  1. When I started reading your dialogue, I was thinking to myself I was pretty lucky not to be bothered by pollen allergies much, except for scotch broom, which I discovered my first year living here in Washington state. Then you mentioned it….and I know I’m not alone. I’m glad my neighbor bush hogged all the ones that were growing on his property last summer, so my allergies this year were not so bad.

    Liked by 1 person

    1. Yes, very similar plants of the same group are known as French broom and Spanish broom, so “common broom” is sometimes used to refer to the apparently more common Scotch broom. In Australia, they call it English broom 🙂


  2. This was so interesting. I really enjoy learning about your personal experiences with a large dose of science and research. The best of both a personal blog and a science blog. Well done. P.S. I hate the smell of Scotch Broom. It took me years to figure out what that awful smell was along the highways in Colorado.
    My sister discovered she was allergic to shellfish when she had to go to the ER during college.

    Liked by 1 person

    1. Thanks, Shelle! Glad what amuses me is of some benefit to others 🙂

      I loved the bit of folklore, about Scotch broom’s strong smell taming wild horses and dogs – they must have found it as off-putting as we do!

      Shellfish and other food allergies are nothing to mess with. My own instant reaction to that bite of prawn gave me a greater appreciation for those – kids, especially – who have severe food allergies, e.g. to peanuts, and have to be ever-vigilant (even against their own relatives in some cases) that none of their food is contaminated.


  3. I’m very glad I don’t suffer from allergies since everything is covered in yellow right now. I love to open our windows to the fresh air but always pay the price in daily dusting.
    That scotch broom bush looks a lot like our forsythia.

    Liked by 1 person

  4. Just looking at those pollen bastards in the photo make my eyes itch. My allergic reactions have tempered with age, but one constant, when I bike or run in the spring, my eyes will be red the rest of the day. A couple of weeks ago, a bike ride set off a case of gooey pink eye that lasted over 24 hours.
    When I was a young adult, I got one of those allergy tests. The grass test immediately began swelling up and after ten minutes the doctor decided to give me a shot of Benadryl. The reaction stopped but the swelling didn’t go down and I spent a whole weekend with a swollen arm.

    Liked by 1 person

  5. Rebecca,
    I loved the picture of the bee covered in pollen. This was really eye-opening, which leads to eye-itching during pollen season. In Texas, that would appear to be about 364 1/2 days a year. I have miserable allergies and asthma. I live on albuterol, steroids, Xolair and Claritin. One of these days, I should probably move to some place less polleny, but no where cold. Got any suggestions? Mona


    1. Sorry, Mona, both that your suffer so much from allergies and asthma, and that I must admit I have no non-cold, allergen-free locations to suggest!

      One reason I love winters here is the lack of allergens in the air and no dust from the nearby gravel road. Trade-offs.

      I will say, though, that one of the best moves I made in terms of my in-home allergies – dust, mold and dander – was to move to a drier climate (Seattle was so damp) and ditch carpeting for concrete floors. Hardwood would do as well. No curtains, either. I made a concerted effort to eliminate things that collect dust, mold and/or dander from inside my home.


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