Mini Crash Course on Plants + Pollen

What's the deal with plants? Like, where do I start if I know...nothing? You can start right here!! Okay, so there are a lot (and I do mean a lot) of different ways we classify plants. but for the purposes of this post, I'm going to to break down a few of the key ones in a way that (hopefully) isn't too overwhelming.

The Linnaean Classification system: This is the standard method of classifying all living organisms, using taxonomic binomial nomenclature (a formal, 2-part naming system in Latinized forms).

🌱 FUN FACT: Common names of plants often vary from region to region, culture to culture, and era to era. You can learn a lot from a plant's common name, and often a lot more from its binomial nomenclature. For example, the plant known as Common Sneezewort (Achillea ptarmica) derives its binomial species name (ptarmica) from the Greek word ptairo ("sneeze") which means "causes sneezing!" -- Thus, the plant's full scientific name translates to "Yarrow that causes sneezing." Pretty on[in?]-the-nose if you ask me.

Do all plants produce pollen? Nope! Not all plants produce pollen. I've put together the following chart which helps break down how we further classify plants --specifically in the context of what plants produce pollen and how they are pollinated, which all leads us to understanding what makes them more/less allergenic and why...we'll get into shortly.

Why do plants produce pollen, and what exactly is pollination? It's how plants get it on, bay-bee! 🐝 Pollination is how the male parts of a plant transfer genetic material to the female parts of the plant, allowing plants to produce seed and fruit, and ensure the genetic diversity of its species is maintained. Let's talk about it!

Reproductive Categories: Both Angiosperms (flowering) and Gymnosperms (non-flowering) have male structures which produce pollen and female structures which develop seeds and fruit.

In Angiosperms, the part of a flower containing the male reproductive organs is called the stamen. At the tip of the stamen is the anther, which is where pollen is produced! The part of a flower containing the female reproductive organ is called the pistil, which contains the ovary. Once fertilized by pollen, this part develops into the mature fruit/seed.

Flowers (and cones) can be male, female, or bisexual -- and there are even more categories I'm not going to get into but...Nature is queer, y'all! And it's awesome.

Monoecious plants have both male and female unisexual flowers on the same plant, which means they are self-pollinating. Examples include: Birch, Oak, Spruce, and Pine trees; and vegetables like pumpkins, cucumbers, corn and tomatoes. Dioecious plants have unisexual male and female parts on separate plants, and need to be cross pollinated in order to produce seed. Examples include: Juniper, Poplar, Maple, and Willow trees; and vegetables like asparagus and spinach.

🌱 FUN FACT: On monoecious conifer trees, female cones grow on the upper branches of the tree, where they can be fertilized by the pollen of male cones blown upwards from the wind.

Okay, so exactly how are plants pollinated? Biotic Pollination (by animals - primarily insects, but also birds and small mammals). In exchange for pollination services, these plants provide animals with food (pollen is very high in protein and nutrients).

Abiotic Pollination (by natural phenomenons - like wind, rain, or water). These are strong, independent self-pollinating plants who don’t need no bugs.

What makes some plants more allergenic than others? It all has to do with how they're pollinated!

Insect-pollinated plants generally tend to be the least allergenic, as the pollen grains are generally larger and stickier, allowing them to easily stick to insect bodies. I mean, just look at these guys. They’re absolutely lost in the sauce:

Wind-pollinated plants, on the other hand, tend to be the most allergenic as their pollen grains are smaller and lighter. They also tend to produce a lot more of it in quantity, since their distribution method is a lot less targeted (they rely on the variable forces of wind and water vs relying on, say, a bee that is reliably going to fly from flower to flower).

Depending on the anatomical structure of a species’ flowers, it may be both animal and wind-pollinated. Privet, for example, is primarily insect-pollinated, but because it has anthers that protrude considerably from its flower (hubba hubba), its pollen can be distributed by the wind, as this article explains.

🌱 FUN FACT: Some bees have special structures known as pollen baskets (or corbiculae) to help them efficiently store and carry pollen!

How is allergy season defined? The peak flowering/pollen times for plants varies by region, even if the same plant species grows across a wide geographical range. This is influenced largely by climate, and may vary slightly year-by-year. Ragweed, for example is abundant throughout all of central-eastern continental US, but pollen levels may peak at different times, depending on what state you're in (the state of allergic misery perhaps). For example, someone who usually prepares accordingly for ragweed season to hit them in mid-September where they live might be in for a bit of a surprise if they travel to another part of the country in mid-late August...!

What is hay fever, exactly? Is it the same as seasonal allergies? Essentially, yes. Hay fever is actually bit of a misnomer, as it was originally believed that the scent of freshly-cut grass (later dried to be used as hay*) was triggering allergic symptoms. Grass pollen of course can be a major trigger for allergies, nowadays the term is used almost interchangeably with the more-accurately described allergic rhinitis. *Consider also, if you really want to put your character in a Situation, the fact that dried hay often contains not only pollen, but mold spores and dust/dried plant particles...

Why does pollen make people sneeze? In simple terms: pollen allergies are an immunological response to the proteins found in different types of pollen. This article, titled 'Allergies: The Radical Theroy of Sneezing' goes into much further detail. Also, um, hello?!!? That name???

🌱 FUN FACT: This paper is the first recorded medical description of 'hay fever.' In case you want to read it. For science, obviously.

A Selected List of the Sneeziest Plants

🌻 wildflowers + weeds

Asters, Daisies, Sunflowers (Members of the Asteraceae family) in general  Ragweed (members of the Ambrosia genus): specifically Common Ragweed (Ambrosia artemisiifolia) and Great Ragweed (Ambrosia trifida) Mugworts (members of the Artemisia genus) - particularly Common Mugwort (Artemisia vulgaris) Pigweed (members of the Amaranthus genus) Goosefoot (Chenopodium album)

💐 cultivated or cut flowers

Baby’s breath (Gypsophila paniculata) and its relatives in the same genus Chrysanthemums or 'Mums' (members of the Chrysanthemum genus) Asters, Daisies, Sunflowers (Members of the Asteraceae family), including: Dahlias (members of the Dahlia genus) Gerberas (members of the Gerbera genus) 

🌾 grasses

Timothy grasses (members of the Phleum genus) Sweet vernal grass (Anthoxanthum odoratum) Bermuda grass (Cynodon dactylon) Kentucky bluegrass (Poa pratensis) Ryegrass (members of the Lolium genus) Orchard grass (Dactylis glomerata) Bahia grass (Paspalum notatum)

🌳 shrubs/small trees

Common Sagebrush (Artemisia tridentata) Hazels (members of the Corylus genus) Juniper (members of the Juniperus genus) Cypress (members of the Cupressaceae family) Privet (members of the Ligustrum genus)

🌲 trees

Alder (members of the Alnus genus) Ash (members of the Fraxinus genus) Beech (members of the Fagus genus) Birch (members of the Betula genus) Cedar (members of the Cedrus genus) Elm (members of the Ulmus genus) Hickory (members of the Carya genus) Maple (members of the Acer genus) Mulberry (members of the Morus genus) Oak (members of the Quercus genus) Olive (members of the Olea genus) Sycamore (members of the Platanus genus) Poplar (members of the Populus genus)

🌱 FUN FACT: People who are allergic to the pollen of one plant species are more likely to also be allergic to species in the same plant family. For example, those who are Ash tree pollen may also be allergic to the pollen of Olives and Lilacs, as all three are members of the Oleaceae family.

🏅special mentions (plants that may or may not necessarily be allergenic but still deserve to be mentioned)

Highly fragrant plants (known to or most likely to trigger scent reactions) Lilies – particularly Asiatic hybrids such as Lilium orientalis (aka the Stargazer lily) Hyacinths (members of the Hyacinthus genus) Lilacs (members of the Syringa genus) Wisteria (members of the Wisteria genus) Lavender (members of the Lavandula genus) Jasmine (members of the Jasminum genus) Freesias (specifically the highly fragrant Antique White Freesia aka Freesia alba) Viburnums (Specifically the Burkwood Viburnum aka Viburnum × burkwoodii) Roses (members of the Rosa genus)* *There are certain types of hybrid Roses that have been bred specifically for traits like fragrance (eg. the variety known as “Mme Isaac Pereire”) but honestly...most of my knowledge pertains to wild rose species and I'm not researching this topic any further because people who grow cultivated/hybrid roses can be Extremely Serious about it and I’m genuinely a little scared of them. Small, fluffy seed heads (wind-distributed seeds that are very tiny and light and easy to breathe in...Do you see where i'm going with this? You see the vision?!) Dandelions (Taraxacum officinale): Willowherbs (members of the Epilobium genus) Cottongrasses (members of the Eriophorum genus) Asters (members of the Aster genus) Goldenrods (members of the Solidago genus) Pearly Everlasting (Anaphalis margaritacea) Hypoallergenic plants (these species tend to have thick/sticky pollen that does not become airborne, or needs to be intentionally disturbed by specialist polinators in order to disperse). A pollen allergy to any of the following plants would extremely unlikely, but an objectively hilarious affliction to give to a character. Orchids (members of the Orchidaceae family)Cactus (members of the Cactaceae family) Irises, Crocuses, and Freesias (members of the Iridaceae family) Columbines (members of the Aquilegia family)

🌱 FUN FACT: Many flowers have been cultivated (intentionally bred or hybridized to for specific traits) to produce less pollen. We call these varieties "cultivars." For allergy sufferers, hypoallergenic cultivars are great to grow in their garden (or to purchase at a florist). For pollinators who expend energy to search for a food source, it's not so great. It's even less great if these cultivars are native species which are subsequently planted or introduced into the wild, as it can compromise the genetic integrity of that species' wild populations, and negatively impact native pollinators.

💥 Sternutatory or Errhine plants Sternutatory (adjective): Also sternutative. causing or tending to cause sneezing Errhine (noun): a medicine to be snuffed up the nostrils to promote sneezing and increased discharges.

Important Disclaimer ⚠️ DO NOT TRY THESE AT HOME ( I cannot stress this enough). This is for information purposes only and should not be used as a how-to guide. Many plants, including some on this list and the resources at the end of this guide can be extremely toxic, dangerous – or even deadly – if used, consumed, or prepared incorrectly. Misidentification of plant species can also be deadly. Seriously, do not be silly in your pursuit of snz. Stick with chhinkni, folks.

Wait, so…plants can make you sneeze even without pollen? Heck yeah, friends! We've all heard about pepper as a snz trigger, of course...Well, Black Pepper is just the common name for the plant also known as Piper nigrum. Peppercorns are its dried fruit, and it's what we grind up to get black pepper seasoning! And chhinkni? It's all plant parts! We'll get into that later, too.

Indigenous peoples around the world have been using plants medicinally for millennia. Traditionally, sternutatory (yes, that is the fancy scientific word for ‘sneeze-inducing’) plants were used to treat or cure the common cold, headaches, or in some cases as a stimulant. Are you writing a fic with a character who is an herbalist, traditional medicine practitioner, healer, witch/wizard, etc? Perhaps they would be familiar with some of the following plants:

Sneezeweed (Helenium autumnale) - [crushed dried leaves and flower heads] Sneezewort (Achillea ptarmica)  - [dried powdered roots; possibly leaves?] Sneezewood (Ptaeroxylon obliquum) - [powder from wood, bark] Spreading Sneezeweed (Centipeda minima) - [squeezed flower heads] Kentucky coffeetree (Gymnocladus dioicus) - [dried crushed roots; dried crushed pods] Spanish chamomile (Anacyclus pyrethrum) - [powdered roots] Leopard’s Bane (Arnica montana) - [freshly crushed flowers; whole plant; dried/powdered] Scarlet Creeper (Ipomoea hederifolia) - [roots] Redberry (Deeringia amaranthoides) [powdered roots] Cypress vine (Quamoclit pennata) - [powdered roots] Ipecacuanha (Cephaelis ipecacuanh) - [dried roots and rhizomes] Southern Wax Myrtle (Myrica cerifera) - [powdered root bark] and its relatives Box Myrtle (Myrica Esculenta) and Swamp Bayberry (Myrica caroliniensis) Yopo (Anadenanthera peregrina) - [dried pulverized seeds] Mouse-ear hawkweed (Pilosella officinarum) - [leaves] Lemon balm (Melissa officinalis) - [powdered] Betony (Betonica officinalis) - [powdered herb/dried leaves] Rosemary (Rosmarinus officinalis) - [dried powdered leaves often added to snuff powders]Bee Balm aka Wild Bergamont (Monarda fistulosa) - [dried tops of the plants] Pasque Flower (Pulsatilla vulgaris) [dried roots] Horse Chestnut (Aesculus hippocastanum) - [powder of the dried nuts] Sage, Marjoram, and Tobacco [referenced here as a “gentle” sternutative]

🌱 FUN FACT: Mugwort is considered one of the most important herbs ("the mother of herbs") in traditional medicine (and witchcraft, allegedly). It is both a sternutatory plant and a highly-allergenic plant. It sure would be a shame if your herbalist/healer/witchy character had to both grow/harvest it and prepare/pulverize it...

Okay, but how and why exactly do these plants make us sneeze? Excellent question, so let's get into it! Come on over to...

The Chhinkni Corner

Ever wondered why Chhinkni works? Why it's so effective? What the ingredients are? Exactly how/why these ingredients make us sneeze? Let's dive into some plant + snz science (Snience)!

First, let's break down the ingredients of Chhinkni:

Skimmia laureola [leaf, powdered] Box Myrtle (Myrica Esculenta) [bark, powdered] Indian sandalwood (Santalum album) [wood, powdered] Camphor tree (Cinnamomum camphor) [extract] Peppermint (Mentha piperita) [extract] Southern Blue Gum (Eucalyptus globulus) [oil]

Well, we know from the list of (some of the known) sternutatory plants above that the root bark of Myrica species is sternutatory, so that makes sense! But what about the others on this list? Let's get back to that important question:

What about these specific plants/plant parts make us sneeze? It all has to do with Transient receptor potential channels (TRP channels). TRP channels are primarily located on the plasma membrane of our cells. They detect environmental stimuli and translate this exposure into sensations of chemesthesis (irritation, burning, cooling, tingling) pressure, taste, and smell. There are six main categories of specialized TRP channels, which play different roles throughout our body. Here's a chart that helps visualize each category:

Woah, this is getting a little overwhelming. What the heck does this have to do with snz? Or plants?! Everything, my friend! Everything! Many TRP channels are heavily expressed in the epithelial cells of nasal mucosa. Each TRP channel is activated by different things (with some overlaps) including different chemicals found in specific plant families. Let's look at some of these TRP channels (and what activates them) and things will start to make a lot more sense:

TRPV is activated by: --- Capsaicin (found in Chili Pepper), Piperine (found in Black Pepper), Carvacrol (found in Bee Balm), Camphor (primarily found the Camphor tree, but also found in plants like Rosemary), Menthol, Cannabis, Incense, Ginger, Menthol (mint). TRPA is activated by: --- Mustards (mustard, radish, horseradish, wasabi), Cinnamaldehyde (cinnamon), Tobacco, Cannabis, Wintergreen oil (aka what gives mint candies/gum its flavor), Shogaols (found in Ginger and Sichuan peppers) TRPM is activated by: --- Eucalyptol (oils from Eucalyptus plants), Menthol (mints),  --- Cold temperatures

Hmm...does anything on this list sound familiar in a snz context??!?!?!?!

Wait, is this why things like pepper, cold temperatures, mint, spices, and strong smells make people sneeze? It sure is! When certain TRP channels are activated, they send signals to your body that trigger protective reflexes (eg. sneezing and coughing) to get rid of the irritant. Everyone's cellular make-up is as unique as they are, and we all react and respond to external stimuli in different ways. Some people might only get a runny nose when exposed to cold temperatures, while for others it might trigger sneezing.

🌱 FUN FACT: There have been studies examining TRP channels in the nasal cavity and the role they might play in allergic rhinitis. There have also been studies on specific TRP receptors in the nasal mucosa comparing patients with and without allergenic rhinitis. There is even this study on the nasal effects of camphor, eucalyptus, and menthol!

Learning Tools and More Resources

See where plants grow on a map: Want to know where specific plants grow? Input the plant species (or the genus or family -- now that you know what that is!) into the search bar, and it will show you its global distribution range based on user-submitted data. You can also narrow results down to a specific area. Note: This data is compiled through user-submitted data and may be erroneous. For best results, filter search results using the “Research Grade Observation” option. While the results don’t provide insight on historical range, native vs. introduced species, it’s a great tool to get you started! Pollen Allergen Tool: An interactive chart that shows common allergenic proteins and which plants produce pollens containing them. Repeated Disclaimer ⚠️ The following resources are shared for information purposes only. Many plants, including some on these lists are extremely toxic, dangerous – or even deadly – if used, consumed, or prepared incorrectly. Sternutatory Plants: A list of sternutatory plant species compiled by the USDA Sternutatory Plants: A second list, compiled using various data sources. This paper published in 2021 on the use of sternutatory plants in herbal medicine, TRP activity. and this banger of a quote: "Sneezing had great significance and value throughout history; it exerted a strange fascination on humans" I protest the use of past-tense, but alas. Folks, this paper is Snience (Snz Science) in action. If the following excerpt is any indication:

The End!!

THANK YOU for reading if you got this far, and congrats on making it to the end of this post! I hoped you learned as much as you horned (if not more) and I hope this little guide can come in handy one way or another.

As I mentioned at the beginning of this post, if you ever have any questions on any of these topics, please feel free to reply to this post (or send me an ask if you prefer to be anonymous) and I'll do my best to answer! 💚🌿