How to Identify Ragweed
Before we identify ragweed, of which this article will identify two species for you, let’s clear the air as to the source of allergies. For decades, late summer allergy sufferers used to blame goldenrod for their hay fever. Here in North America, there are over 75 species of goldenrod in the genus Solidago, which by the way is in the Asteraceae plant family. The reason poor, beautiful, AND useful goldenrod got the blame was because its bright yellow showy clusters of flowers bloomed at the same time as ragweed. While ragweed, with its teeny tiny little greenish/pale yellow flower blossoms, inconspicuously bloomed away. Finally, people are now understanding where the blame truly lies.
In this article we will identify ragweed by its stem, leaf, and flower; we will also cover its pollen as well as surprise you with the uses of ragweed, and I’ll list some natural remedies we have found helpful when dealing with seasonal allergies.
How to Identify Ragweed: Two Species: Common and Giant
This article is going to identify two species of ragweed, both of which are in the Ambrosia genus. They are commonly called common ragweed and giant ragweed. Common ragweed’s Latin name is Ambrosia artemisiifolia and giant ragweed’s Latin name is Ambrosia trifida, and these ragweeds are also in the Asteraceae plant family. There are around 50 species of Ambrosia and approximately 17 species in North America.
Artemisiifolia can grow by itself as a single plant, but I often see it growing in larger colonies especially in areas that are undisturbed. It can grow 1 foot tall or even up to 4 feet tall. Artemisiifolia can spread by seeds or by rhizomes, but to me, it seems to spread more readily by rhizome.
Trifida can also grow as a single plant by itself, but it too can grow in groupings in undisturbed areas. It can grow several feet tall; I have seen one plant 15 feet tall and have read where someone saw a 20 foot tall trifida ragweed! Trifida can spread through seed and rhizomes, but it seams to spread more readily by seeds.
How to Identify Ragweed: Stems
When you go to identify ragweed, note that the stem of artemisiifolia has very dense soft hairs or fuzz along the stem. Also the upper part of each leaf stem will be tinged in purple while the underside of the leaf stem is green. Usually the higher up the plant, the more dense or fuzzier or longer the hairs get.
The stem of trifida has much shorter and more sparse hairs than that of artemisiifolia. Neither hairs sting nor hurt, but you can rub the hairs off of the trifida species. The trifida species may or may not have purple tinges of color on the upper part of its stem and branches. I hear some do, but I have never noticed purple coloring on the ones I have encountered.
The stems of both species are round and solid. When I twist them and bend them, they smell like a carrot to me, which could explain why another common name is carrot weed. The main central stem of the trifida species can get quite stiff and woody.
Let’s talk about how to identify ragweed by the arrangement of its branching leaf stems up the central stem. Here’s the short version. HAHA. You can’t…probably. Each plant makes its own rules and each plant within the same species may decide to arrange their branching leaf stems differently. Here’s how mine are.
The branching leaf stems coming off the main central stem of artemisiifolia are often opposite of each other, but as you get closer to the top of the plant, they decide to go in an alternate pattern as is shown in the photo.
The branching leaf stems coming off the main central stem of trifida are actually opposite each other, but I want you to look closely at the above picture showing the arrangement of the trifida. Do you notice anything interesting? Start at the top of the main central stem and go down slowly until you find where it branches off and note the direction; it’s opposite, but it’s pointing north and south. Go down to the next branching set and note it’s still opposite, but now its direction is east and west. It alternates direction while still being opposite! Now, here’s another thing. NOT all trifidas do this, some will all branch out the same direction. The trifida species is HIGHLY variable.
How to Identify Ragweed: Trifida Leaves
The trifida species can have highly variable leaf patterns. You can see in the photo where I circled in white, the leaf is a single simple leaf with no lobes. The yellow circle has two lobes, and the purple outline has 3 lobes. The three different leaf shapes are on the same trifida species plant. Remember the trifida species is a highly variable plant, and its leave can vary between one simple unlobed leaf up to a leaf with 5 lobes!
The midrib or middle vein, on the top and underside of the trifida leaf, has little hairs. Also, the leaves are somewhat scratchy, and they feel like sandpaper and sound like a fine sandpaper when you rub the leaf against itself.
While crushing the leaf, the plant emits an aromatic scent. I personally find the scent pleasant, but many do not. I cannot quite put my finger on the smell, but it’s reminiscent of a camphor type scent. I have smelled this scent in both species but find it is stronger in the trifida species.
While it is the pollen from ragweed that causes the majority of the country to sneeze in later summer and early fall, please also understand that individuals may be allergic to the leaves themselves. The leaf could possibly give someone a mild rash, but it is quite rare.
How to Identify Ragweed: Artemisiifolia Leaves
The above two photos help to identify ragweed leaves; this is the artemisiifolia species, common ragweed. The photo on the left shows the top of the leaf while the photo on the right shows the underside of that same leaf.
The top of the leaf is a bit of a darker green while the underside of the leaf is a lighter green. The underside of the leaf stem also has those fine hairs growing.
If you look closely, you’ll see that the leaves are VERY much lobed very much unlike the trifida species or giant ragweed. Also note the leaf structure. As stated each leaf is deeply lobed making it almost appear heavily divided. Some would call this leaf a pinnately compound leaf due to it looking like each leaflet is completely divided from the main central vein on the leaf, and some would simply call this a very deeply divided leaf. Notice how each little leaflet almost appears to wrap around the central leaf stem? This can be seen by looking closely at the leaf stem, you’ll see the lighter colored vein, but then on either side of the light vein, you’ll see the darker green, which is actually the leaf itself. This is why some believe this is simply a very deeply lobed single leaf. However, for all intensive purposes, at a glance, it definitely looks pinnately compound for sure. No matter what you call it, we can all agree it is as different as can be from the trifida species.
Each leaf and leaflet ends with a terminal point at the tip while the lobes below the terminal point are usually more rounded.
The leaves of this species are soft. This softness is completely unlike the trifida species, which is rough like sandpaper.
How to Identify Ragweed: Flowers
The first thing you’ll notice when you go to identify ragweed flowers is that the flower clusters are much less noticeable on the smaller common ragweed, Ambrosia artemisiifolia than on the giant ragweed, Ambrosia trifida.
Notice the flower arrangements on the two previous photos. The tall flower head spikes grow at the very top, the end, of the stem. They grow at the end of each and every branching stem. If you notice, the underside contains little yellow balls, these yellow balls are the pollen producing male flowers. Please note covering the top of the yellow flowers is a green hood. That green hood is why these hay fever causing plants go unnoticed, no one can spot them as their tiny little yellow flowers are hidden. Therefore, poor, bright, yellow goldenrod gets the blame.
Notice the minor differences in the flowers between these two species. The artemisiifolia species’ green hood appears to be covered in more fine fuzz than the trifida species. The trifida species appears to have more solid or stronger looking individual flower clusters whereas artemisiifolia species appears to be softer and more delicate. The trifida species’ individual little flower clusters remind me of little condos.
When it comes to these flowers, there’s something to note. Each little yellow flower ball does NOT contain both male and female parts. The flower pictures above are all male flowers and produce the pollen. By the way, the pollen is produced from mid August to the first frost each year at least here in Missouri.
When you go to identify ragweed, keep in mind the interesting part of how each plant has separate male and female flowers. You saw the two photos showing the little yellow male flower balls. Now, try hard to find the female flowers. The photo on the left shows some female flowers down in the leaf axil below the male flower raceme. The photo on the right is a closer up.
You’ll notice the female flowers are not yellow but green and you can ID them by those two little light yellowish green thread like looking things. Those are the styles of the female flower. The styles are what connects the stigma to the ovary of the female flower. The female flowers always appear later than the male flowers, and in my observation, they don’t appear until after the male has been shedding his pollen for a while. As I write this article, I have noticed the female flowers are literally just beginning to develop and show themselves 2-3 weeks after the male flowers were first visible. The female flowers, if pollinated, will develop the seed. As the seed matures, it will get darker in color like a grayish brown, and it will get little stiff prickles on it, some people call it a burr, this is another way the seed is spread.
How to Identify Ragweed: The Pollen
The pollen from ragweed is light and carried on the wind while the pollen from goldenrod is sticky and heavier and must be transported by insects.
WARNING: Because ragweed is in the Asteraceae family, anyone allergic to other plants in the Asteraceae family may also be allergic to ragweed as well as goldenrod. Just note that the Asteraceae family is the largest plant family in the world.
You may see my video comparing goldenrod pollen to ragweed pollen.
How to Identify Ragweed: Ragweed Uses and Natural Remedies
Now that you can identify ragweed, let’s talk about the uses of ragweed.
While, highly allergenic, ragweed has benefits including:
- food for the wild
- home remedies
- archery
- livestock feed
- detoxing the soil
- improving soil health
FOOD FOR THE WILD:
The seeds of ragweed are important food for several species of wild animals. They are favorite foods of various birds including redwing blackbirds, goldfinches, juncos, certain species of sparrows, bobwhites, and redpolls. They’re also often eaten by ground squirrels and least chipmunks.
HOME REMEDIES:
Native Americans would use ragweed internally and externally. Ragweed can be used for issues such as menstrual cramps; reducing fevers; insect bites and stings; it has astringent and antiseptic properties, emetic and emollient properties; it may help with nausea and may act as a laxative; it has been used in many other ways too, but here’s the ironic use. Ragweed pollen is one of the top, if not the number 1, hay fever causing plants in the world. The ironic thing is that it is also used to TREAT hay fever. The pollen is harvested and used in immunotherapy for the treatment of allergies. How interesting is that. We personally have yet to try it for allergies, but I do currently have some ragweed tincture in the making, and I have been waiting on some more leaves to grow after being mowed down and then also eaten on by some bugs. I plan to dry the leaves to use for tea as well.
To make the tincture, you may use fresh, wilted, or dried ragweed leaves. Again make 100% positive ID and it’s best to ID once the plant sends up the flowers spikes but BEFORE it actually begins to flower and release pollen. You do NOT want to harvest pollen covered leaves. Simply fill a jar with the fresh or wilted leaves or fill the jars half full with the dried leaves and cover with 80 proof or 100 proof vodka. Cap tightly, label, and shake daily to make sure the plant material stays below the alcohol. Add more alcohol if needed. Keep in a dark place again shaking daily. Let sit for 8 weeks. Use as needed. ALWAYS start with small doses, as in 1 DROP at a time and work up to 2 drops and so on until you find the dose that works for you.
You can find more about the medicinal benefits of ragweed here.
WARNING: If you decide to use ragweed, remember most people are highly allergic to it. Also ALWAYS make 100% positive ID of the plant. There are some look alikes such as mugwort; motherwort; wormwood; southernwood; chrysanthemum; tansy; queen anne’s lace; and there may be others. It’s always best to wait to ID a plant once it is flowering.
ARCHERY:
I have also come across where some people make Atlatl darts using the hard woody stalk of the giant ragweed plant, Ambrosia trifida. I cannot find much on it, but I have come across some mentionings of the stalk and stems of the trifida species being used as cordage or rope.
LIVESTOCK FEED:
I have come across several articles stating how ragweed was at one time cultivated for food by the Native Americans then also for livestock feed later on. I read the Native Americans would cultivate the plant for the seeds to eat in the winter. The seeds are very high in protein and in oils.
I wanted to share this article with you. It shows the protein content of ragweed, as well as some other weeds. It also mentions how when you train your animals to eat certain, non-toxic, weeds to make sure those weeds are not full of nitrates, which can poison your livestock. This video shares a bit on training animals to eat certain weeds. Something to keep in mind if you would like to cultivate or harvest ragweed for your cows, sheep, and goats is that from my research it appears the giant ragweed is the preferred species.
I found this article an interesting read.
This guy adds dried ragweed to his pig slop.
SOIL DETOX and IMPROVEMENT
In more recent times, it has been learned that ragweed can detox and improve soil health by removing heavy metals such as lead from the soil. Ragweed can also help clear up industrial waste. However, if you decide to use ragweed to detox the soil, I highly recommend to burn the mature plants and not compost them as that will just be adding those toxins back into the soil.
Apparently, people have known about this detox ability of ragweed for two or three decades now as a patent was filed on using ragweed to remove lead from soil.
HOW WE COMBAT ALLERGIES
Thankfully I am not one that is very much bothered by ragweed; in recent years, I do notice my eyes are itchy for a moment, but it doesn’t give me sinus trouble like it does many others. However, my husband and youngest daughter have a rough way to go with it. Over the years I have found that if my family starts drinking nettle tea, Urtica dioica, daily, preferably before the pollen starts shedding, they no longer get a full blown upper respiratory distress when encountering ragweed like they had in years past. In addition to nettles, they say local raw honey is beneficial as is goldenrod; chamomile; butterbur; mullein; and of course, ragweed itself: just remember the warnings associated with ragweed.
I hope you found this article helpful, if so, please share it with others!
