Tall Thistle

Cirsium altissimum

SIR-see-um  al-TISS-ih-mum

Synonyms of Cirsium altissimum (10) (Updated on 11-30-23 from Plants of the World Online):  Carduus altissimus L., Cirsium altissimum var. biltmoreanum Petr., Cirsium altissimum f. moorei Steyerm., Cirsium diversifolium DC., Cirsium filipendulum Engelm., Cirsium iowense Fernald, Cirsium iowense var. crattyii Pammel ex Wolden, Cnicus altissimus Willd., Cnicus iowensis Pammel, Cnicus iowensis var. crattyii Pammel

Cirsium altissimum (L.) Spreng. is the 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 volume of the first 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.

As of 11-30-23 when this page was last updated, Plants of the World Online by Kew lists 378 species in the Cirsium genus. It is a member of the plant family Asteraceae with 1,702 genera. Those numbers could change as updates are made on POWO. The number of genera in this family fluctuates quite often.

The above distribution map is from Plants of the World Online. Areas in green are where the species is native. The map on the USDA Plants Database.  is similar. Plants of the World Online get their data for maps in North America from Flora of North America.

The map on iNaturalist shows where members have made observations. Anyone can join and it is a great website to confirm and share your observations. The maps on iNaturalist are continually updated as members post new observations.

Being a native species, this plant is beneficial for native species of birds and insects and it is usually not as invasive as non-native Thistles. Without even keeping it in check, there are only a few of these plants on the farm while we battle Bull and Musk Thistles which are not native.

THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND BETTER POSITIVE ID.

I first ran across a few of these very tall plants in July of 2019 along the trees in the southeast corner of the farm near a swampy area. The area is somewhat hard to explain… Anyway, I had just scratched the surface of identifying wildflowers on the farm, so I had no clue what they were at first. The plants had several “thistle-looking” buds, but there were no flowers yet. I am well acquainted with Bull Thistle (Cirsium vulgare) and Musk Thistle (Carduus nutans), and these were definitely not them. I took a lot of photos, then looked on the Missouri Plants website for an ID (that was before I started using iNaturalist). Looking at photos on Missouri Plants, I decided I had found Cirsium altissimum, commonly known as Tall Thistle. I thought that was pretty neat. A native thistle without the spines! Over the years, most of the time there have just been a few plants in the back pasture and along the edge of the south hayfield. But, there have been a couple of large colonies in the south hayfield as well when the conditions have been just right… 

Cirsium altissimum is a biennial or short-lived perennial in the plant family Asteraceae. It is native throughout Missouri and from the midwest United States eastward. This species is characterized, not by its spines, but by the lack of spines. I call it the “user-friendly” thistle. It is also distinguished from other thistles by its mostly unlobed and undivided leaves (except for the basal leaves) that have white undersides. 

Cirsium altissimum, being a biennial, produces a rosette of leaves the first year then a tall stem, up to 8’, the second year in optimum conditions. They can be found growing in full sun to part shade in fertile loam, clay-loam, or sandy-loam soil in wooded areas, the edge of wooded areas, in prairies and pastures, along roads… Well, you get the picture. They will grow just about anywhere, but like a little shade to be their best. They appreciate moist conditions (like most plants), but are drought-tolerant as well. Dryer conditions in full sun will cause their lower leaves to dry up and fall off.

The above photo is of a shorter plant growing in full sun between the main hayfield and back pasture in 2019. Being in full sun, it was shorter and the basal leaves had fallen off.

There are more photos at the bottom of the page.

If we divide this plant into 3 parts we can get a pretty good idea of what the Cirsium altissimum is all about.

The thick stems stand erect and are ribbed, branch out at the upper 1/3, and are light green to reddish brown. The stems have stiff white hairs (pubescent), becoming mostly hairless (glaucous) father up, sometimes with wooly patches of short white hairs toward the top. The stems are probably the roughest part of the plant.

The leaves grow alternately along the stems.

The lower leaves (basal) grow alternately on the lower 1/3 of the stem. The lower leaves are maybe at least 12” wide and 4” across, getting smaller as they ascend the stem. Descriptions online say their shape is narrowly ovate, elliptic, obovate, lanceolate, or oblanceolate in outline. Take your pick… Most of the plants here have deeply lobed basal leaves and the lobes gradually disappear as the leaves ascend the stems.

The leaves may be sessile (no leaf stems), have short petioles (leaf stems), or clasp the stems. The upper surface of the leaves is dark green, glabrous (no hairs), or may be finely pubescent (hairs), while the under surfaces have fine wooly white hairs.

Stem leaves begin about 2/3 of the way up the stem, ummm, more or less. Although some central leaves may have teeth, they aren’t really “spiny”. The margins of the leaves are slightly wavy, spineless, and taper to a single short spine…

Oh, the small leaves toward the top of the branches have fairly long spines, as do the 2-4 leafy bracts that surround (subtend) the heads.

The main stem branches out at the upper 1/3 of the plant and the branches usually terminate in a single flower head, but I have seen a few that have 2-3 heads. There are usually a lot of flowers because there are a lot of branches.

The globular to vase-shaped flower heads are approximately 2” across. Since it is a thistle, there are no ray florets. The heads are mostly covered with many appressed overlapping involucral bracts with light yellow to white midribs (some sites may call these phyllaries or floral scales). The bracts taper to a dark tip and most have a sharp spine.

Sticking out of the top of the head are numerous pink to reddish-purple tubular disc florets with an exerted style.

The flowers of one plant were pink…

It’s amazing how many buds and flower heads have webs around them.

This 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. Assassin bugs are great opportunists.

I 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.

Flowerheads are replaced by a mass of seed, called achenes, which have tufts of white hairs that allow them to float in the wind. The seeds are a favorite of many species of birds. The American Goldfinch uses the “hair” to line its nests.

The nectar of the flowers attracts several species of bees, butterflies, and clearwing moths. Beetles, grasshoppers, caterpillars, and aphids feed on the leaves.

USEFUL INFORMATION:
Family: Asteraceae.
Origin: U.S. native (midwest-eastern half).
Zones: USDA Zones 4a-10b (-30-35° F).
Size: 3-12’+.
Light: Sun to part shade.
Soil: Prefers moist soil.
Water: Prefers to have regular watering.
Flowers: Pinkish-purple, reddish-purple, rarely white .

Wikipedia says, “The word “Cirsium” is derived 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.–

I will continue adding more photos and information as time goes by. I always need better ones…

I have enjoyed photographing and learning about the many wildflowers growing on the farm and in other areas. The farm is in Windsor, Missouri in Pettis County (Henry County is across the street and Benton and Johnson aren’t far away). I have grown over 500 different plants and identified over 250 species of wildflowers (most have pages listed on the right side of the page). 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 few horticulturalists 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. Some sites may not be up-to-date but they are always a work in progress. 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 thebelmontrooster@yahoo.com. I would enjoy hearing from you especially if you notice something is a bit whacky.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
TROPICOS (GENUS/SPECIES)
FLORA OF MISSOURI (GENUS/SPECIES)
FLORA OF NORTH AMERICA (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
USDA PLANTS DATABASE
MISSOURI DEPARTMENT OF CONSERVATION
DAVE’S GARDEN
MISSOURI PLANTS
MSU-MIDWEST WEEDS AND WILDFLOWERS
iNATURALIST
WILDFLOWER SEARCH
ILLINOIS WILDFLOWERS
MINNESOTA WILDFLOWERS
LADY BIRD JOHNSON WILDFLOWER CENTER
KANSAS WILDFLOWERS AND GRASSES

NOTE: The data (figures, maps, accepted names, etc.) may not match on these websites. It depends on when and how they make updates and when their sources make updates. Some websites have hundreds and even many thousands of species to keep up with. Accepted scientific names change periodically and it can be hard to keep with as well. Some of the links may use a name that is a synonym on other sites. In my opinion, Plants of the World Online by Kew is one of the most reliable and up-to-date plant databases and they make updates regularly. I make updates “at least” once a year and when I write new pages or add new photos but I do get behind. We are all a work in progress. 🙂

MORE PHOTOS…

 

 

[The basal leaves of the plants growing in more shade are very long, broader toward the end, and deeply lobed.  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… The heads become more vase-shaped as the disc florets emerge.

 

 

The basal leaves on this plant are very long and elliptic (broad in the middle, tapering at both ends).

 

Then the heads become more ovate-shaped when the buds start to open.

 

 

 

One plant had lighter pinkish-white flowers but the rest of the plants had more pinkish-purple flowers.

 

 

 

I took several photos of the Cirsium altissimum along the edge of the south hayfield in 2021. The entire area had grown up in blackberry briars, Japanese Honeysuckle, and small trees. It was mowed off in 2020 and a new fence was put in. Mowing it off allowed a lot of wildflowers to grow I wouldn’t have noticed otherwise. Of course, the blackberry briars grew like crazy again…

 

 

 

 

 

 

 

 

 

One colony in the south hayfield was very tall…

Same colony from the back. I’m not sure how tall they grew…