Cirsium altissimum (L.) Spreng. is the correct and accepted scientific name for the Tall Thistle. It was named and described as such by Curt Polycarp Sprengel in Systema Vegetabilium in 1826. It was first named and described as Carduus altissimus by Carl von Linnaeus in the second edition of Species Plantarum in 1753.
The genus, Cirsium Mill., was named and described by Philip Miller in the fourth edition of Gardener’s Dictionary in 1754. Plants of the World Online by Kew list 458 accepted species in the Cirsium genus (as of when I wrote this page on 8-25-19). The number of accepted species can change at any moment it seems. There were 459 a few days earlier. Version 1.1 of The Plant List (2013) listed 481 accepted species with an additional 68 infraspecific names, a total of 1,800 synonyms, and 512 names still unresolved. The people in charge have been working very hard to get the scientific name ordeal sorted out. The Plant List hasn’t been maintained since 2013 but I still use it to check on progress.
Please refer to the links at the bottom of the page for further reading and more technical information about plant ID.
The top photo is one of three plants growing in the same area. One of the three, the one in this photo, is at least 12′ tall.
I have been very acquainted with Cirsium vulgare (Bull Thistles) and Carduus nutans (Musk Thistles) here on the farm for several years. I only have an occasional Musk Thistle come up and the Bull Thistles only come up in the front pasture and around the barn. Working at a friends farm battling his thistles this past spring and summer was very exhausting for several months. I really enjoyed taking photos and identifying several wildflowers at his farm that I don’t see here. The thistles at his farm were (are) mainly Musk Thistles, probably outnumbering Bull Thistles 10-to-1. Well, there were thousands! There are several thistle species in Missouri and at first I did try to ID more than two species but… After a few months of spraying and digging, I decided I didn’t really care. A thistle is a thistle! While I must admit, the plants and flowers are pretty neat.
This past summer I didn’t have any cows here on this farm so the grass grew up for hay. I didn’t go to the back of the farm like usual to take wildflower photos because the grass became very tall. As soon as the hay was cut, I wasted no time. The first day I identified and photographed several new wildflowers I had not seen before. In a corner of the back pasture (next to a swampy area), I noticed three VERY TALL plants I hadn’t noticed before. There were several more in other areas along the trees in the fence row. I am sure they have been coming up here for several years and have no idea why I didn’t notice them before.
The plants weren’t flowering when I first saw them but their buds looked like some species in the Cirsium genus. After taking a lot of photos I identified the plants as Cirsium altissimum… This was my first encounter with a “user-friendly” thistle.
The Missouri Plants website is a great source of information and has helped me identify more than 100 wildflowers. Their descriptions are a bit technical, but if you are a botanist or horticulturalist you will have no problem. Recently I found out about Missouri State University’s website called Midwest Weeds and Wildflowers. Pamela Trewatha has done a great job with photos and descriptions and is every bit as good as Missouri Plants and is much easier to read.
When photographing wildflowers, I try and get as many photos as possible, usually two or more of the same thing because you never know. Some photos may be blurry and then I have to go back AGAIN (been there, done that). Sometimes I have to go back anyway because I forgot something.
The Missouri Plants website has this to say about the leaves of Cirsium altissimum:
“Leaves – Basal and alternate, sessile or short-petiolate. Basal leaves 10-30 cm long, 4-15 cm wide, narrowly ovate to elliptic or obovate, tapered at the base, usually bluntly angled at the tip, unlobed or rarely with several deep lobes, the margins otherwise toothed or wavy and spiny, the upper surface appearing green, nearly glabrous to moderately pubescent with stiff, straight hairs, the undersurface appearing white, densely pubescent with felty hairs. Stem leaves well developed throughout, the main leaves 4-25 cm long, those toward the branch tips usually somewhat reduced, all unlobed or with shallow (less than 1/3 of the way from the margin to midrib), broad lobes (reduced leaves just below the heads rarely more deeply lobed), tapered to a slightly expanded and sometimes minutely decurrent base, otherwise like the basal leaves.”
So, if we divide this plant into three parts we can get a pretty good idea of what the Cirsium altissimum is all about.
If you look at the second photo, you will see the plant starts branching out about 2/3 way up the plant, more or less. These branches usually end with a solitary bud
The stems are probably the roughest thing about this plant as they are covered with very short and stiff white hairs.
The central leaves begin about 1/3 way up the stem, ummm, more or less. Although the central leaves do have teeth, they aren’t really “spiny”.
Earlier I had read an article about how nutritious thistle leaves and buds are. I thought the guy was a little nuts because who would want to go deal with all those spines. Well, with this plant, it would be easy because there are no spines… Well, at least nothing like the others I have been dealing with. He says the buds are prepared much like artichokes. I am very tempted to try it with these plants… But the guy was talking about eating the spiny thistles… I will pass on those.
The basal leaves of the plants growing in more shade are very long, broader toward the end and deeply lobed. The Missouri Plants website states “basal leaves can be narrow-ovate to elliptic or obovate, usually bluntly angled at the tip, unlobed or rarely with several deep lobes.” As you can see in the above photo, they are very deeply lobed on these plants. However, as you will see farther down this page, the plant growing in full sun does not have lobed basal leaves. In more sun or dryer conditions, the basal leaves sometimes wither and fall off.
The buds are globe-shaped. It appears small spiders have made homes on most of the buds…
Which is probably why a Wheel Bug (Arilus cristatus) was lurking around on the top of a bud. We were eyeball to eyeball and it didn’t seem too thrilled I was there taking photos.
Origin: U.S. native (midwest-eastern half)
Zones: USDA Zones 4a-10b (-30-35° F)
Light: Sun to part shade
Soil: Prefers moist soil
Water: Prefers to have regular watering
Flowers: Pinkish-purple, reddish purple, rarely white
This photo shows the “involucre” surrounding a small bud. The involucre are the leaf bracts that surround the bud or flower.
This one seems a little confused and has more than one bud on this branch…
While most of the Cirsium altissimum plants are growing in the southeast pasture in partly shaded areas (they only get morning sun), this one plant is growing in full sun. It is the same but much shorter and lacks the lower lobed leaves. A few feet away is a similar plant that is VERY spiny but is NOT a Bull or Musk Thistle. It has the same growth habit.
The basal leaves on this plant are very long and elliptic (broad in the middle, tapering at both ends).
The buds are globe-shaped in the beginning…
Then the buds become more ovate-shaped when the buds start to open.
Quite a number of species of bees, flies, butterflies (including Monarch’s), and moths enjoy the nectar of thistle flowers. Beetles, aphids, and caterpillars of butterflies and moths feed on their leaves. There are several birds that also feed on their seeds. The Cirsium altissimum is a native thistle and not necessarily considered invasive. I have been a while, and as I mentioned, I haven’t even noticed them before. Native species feed on this plant keeping their numbers down.
I took a lot of photos but I am running out of words…
The Wikipedia says, “The word “Cirsium” derives from the Greek word kirsos meaning “swollen vein”. Thistles were used as a remedy against swollen veins.” Dave’s Garden says, “Cirsium is from the Greek word kirsion, meaning a kind of thistle.” The species name, altissimum, means tallest.
Each petal on the flower is supposed to have a darker stripe. Hmmm…
One plant does have lighter pinkish-white flowers but the rest of the plants are more of a pinkish-purple.
Now I almost finished… Until I take more photos.
Well, I must admit, I learned a little more about thistles since I found this plant and did some research. Research I would have not done thinking a thistle was just a thistle.
I will continue adding more photos and information as time goes by.
I have enjoyed photographing and learning about the many wildflowers growing on the farm and other areas. I have grown over 500 different plants and most have pages listed on the right side of the blog. I am not an expert, botanist, or horticulturalist. I just like growing, photographing and writing about my experience. I rely on several websites for ID and a horticulturalist I contact if I cannot figure them out. Wildflowers can be somewhat variable from location to location, so sometimes it gets a bit confusing. If you see I have made an error, please let me know so I can correct what I have written.
I hope you found this page useful and be sure to check the links below for more information. They were written by experts and provide much more information. If you can, I would appreciate it if you would click on the “Like” below and leave a comment. It helps us bloggers stay motivated. You can also send an email to me at firstname.lastname@example.org. I would enjoy hearing from you.