|These ox-eye daisy flowers in this Shutterstock image on the Rocky Mountain Allergy Asthma Immunology website has absolutely nothing to do with pollen allergies. They are just pretty flowers.
(Screenshot image by BotanicalAccuracy.com, source.)
|A screenshot from a quick search on the keywords ‘pollen allergy’ on the photo website Shutterstock, shows an abundance of photos of insect-pollinating plants, flowering fields, and dandelion fruiting heads which has nothing to do with pollen allergies. Some photos get it right but not the majority. (Screenshot by BotanicalAccuracy.com, source.)|
Pollen, which are special small cells in seed plants that contain the male sex cells (no, it is not gross, just the fact), are produced in flowers and when the pollen lands on the female part of a flower or cone (the landing platform is called a stigma), the pollen germinates and a pollen tube grows into the female style and down into the ovary where it can fertilize the plant’s egg cell and make a seed. This is not gross, just the facts, and in fact, if there were no pollen, there would be no fruits, no flowers, no seed plants. Seed plants are those that set seed, so that means conifers and flowering plants, but not ferns and mosses, because they have spores instead. Not all pollen causes allergies and neither does all spores.
|Pollen grains from many different plant species shown in a photo from a Scanning Electron Microscope. (Public domain image from Dartmouth College Electron Microscope Facility via Wikimedia Commons, source.)|
So, how does the pollen gets transported from the male to the female part in the flower? Most plants use animals as transport helpers (for bee pollination, etc.), but some plants have wind-pollination. If you are adapted to use wind as the pollination method, then you are going to have some problems to overcome – first, wind is kind of random so you don’t know where your pollen would end up, so you better make LOTS of pollen; second, you don’t want your pollen to stick to anything that isn’t the right stigma, so it needs to be dry and smooth and fly easily; and third, you need to make your pollen-sacs hang out far into the air without interference from large petals, so you can disperse your pollen with every little wind burst. These three evolutionary adaptations are seen in many wind-pollinated plants. So, these plants produce an copious masses of dry, easy-flying pollen from small flowers with hanging pollen sacs. This is exactly how birches, ragweed, grasses, walnuts, mugwort, elms, pigweeds, cottonwoods, and hickories spread their pollen around. And these plants are the ones people who suffer from pollen allergies are allergic to (see caveat below).
|Flowers of a grass, showing stamens with pollen sacs hanging out and spreading their light dusty pollen into our eyes and noses (and to other grasses). (Creative Commons photo by Dave Kleinschmidt, source)|
Many people think they are allergic to goldenrod, this common, yellow-flowered fall flower, but it is insect-pollinated. Plants that are pollinated by insects have 1) something that attracts the insect to the flower, usually sweet smell and bright colors, 2) sticky pollen that gets stuck on the insect, and 3) small amounts of pollen. You can easily tell if a plant is insect or wind-pollinated by looking at its flower and checking if any pollen flies out in the air if you shake it (this only happens in wind-pollinated flowers). There are also plants pollinated by mammals, birds, and other small animals, as well as water, but those are more rare. In North America, the hummingbirds are the only birds that polli
|VividLife illustrates their POllen Allergy Awareness article with a nice, invasive thistle, pollinating insect included. Of course, it has colorful small pink petals (in a big flower head), sticky pollen, and is not something that easily causes pollen allergies. Another blatant example of wrong imagery in the pollen allergy area (Screenshot by Botanical Accuracy, source)|
So, when your neighbor says that he can’t go outside because the dandelions are flowering, or there is a newspaper article about hay fever illustrated with a pretty flower, or your oldish aunt says she is allergic to the pollen of cut flowers in a vase, they will most likely be very wrong. (Some people are allergic to the smell of pretty flowers, but that is different.) Still, the misconceptions are flying like airborne wind-dispersed pollen in advertising, news media, and around lunch tables.
An other prevalent misconception shown in allergy imagery, even on the websites of medical and pharmaceutical companies based on science, is the (non-existent) connection between dandelions’ fruiting puffy heads and allergies. No, you are not allergic to flying dandelion parachute fruits and seeds, despite all those photos and ads showing exactly this connection.
|Article from Mass Lunch & Allergy PC illustrated dandelion heads under the heading Pollen Allergy. Please note that the fruiting dandelion head not only has no pollen in it, it is also a fruit, not a flower. The grass would be the allergen to most hay fever suffers. (Screenshot by Botanical Accuracy, source)|
In this image below, there isn’t even one potential flower and no pollen source at all:
|Freedom Home Care has an article called How to Keep Seasonal Allergies Under COntrol, and it is 100% illustrated with a no-pollen part of an insect-pollinated plant – Dandelion fruiting heads, again. Such misuse of images just creates confusion and makes the public afraid of real nature. (Screenshot by Botanical Accuracy, source)|
So, why does these image mistakes matter? It is just a picture, right? Well, they matter a lot. The public reads the information and associates the allergies with the images that are used to illustrate them. Allergies means medical problems (bad stuff). We start to think allergies when we see canola fields, blowing wishes with dandelion heads, and pretty flowers. It is ‘guilty by association’ and just more of the fear of nature that is spread around in media. Fact checking should not only be for the words but also for the images that goes with the words. Some allergy doctors and pharmaceutical companies are just as guilty as photo databases in this area.
Caveat: This blog post is based on what most people are allergic to that react to pollen. You could become allergic to nearly anything, so a small percentage of people could be allergic to tulip pollen, rose petals, and goldenrod pollen, but that is very, very rare. When testing for allergies, it is the wind-pollinated plants that count.
Links for more information:
American College of Allergy, Asthma & Immunology: Pollen Allergy: Be aware that this webpage has some overly simplistic descriptions about the biology and biodiversity of plants. For example: “Pollen is very fine powder that comes from trees, grasses, flowers and weeds.” and “When a plant begins to flower, its pollen goes into the air.” They need a biologist fact checker. No need to make things so simple fo the public that is becomes wrong.
Many thanks to KS for medical allergy testing information.