Montane, subalpine. Woodlands, openings. Summer, fall.
La Sal Mountains, Utah, August 10, 2020.

Cirsium tukuhnikivatzicum grows in abundance from about 8,000' to over 11,000' (perhaps even above tree-line) in meadows and woodland edges only in the La Sal mountains of Grand and San Juan counties of southeast Utah. The species has puzzled collectors for decades and is often treated as C. scopulorum, C. eatonii, or C. eriocephalum. When I tried to key the plant using all available resources, none of the resources led me conclusively to any species. I sought the assistance of Dave Keil (author of the Cirsium treatment in the Flora of North America), Bob Sivinski (author of the "Thistles of New Mexico"), and Jennifer Ackerfield (author of Flora of Colorado). They all agreed that this taxon was part of a high elevation group of Cirsium that varied widely in its characteristics from mountain range to mountain range. Jennifer offered one further conviction: this is an undescribed taxon which has in the past been incorrectly placed into other species. Jennifer was so convinced of the unique characters of this thistle that she published this taxon as a new species (June 23, 2023).

According to Ackerfield's 2023 description of this taxon,

"The first specimen of the La Sal thistle was collected by Per Axel Rydberg & Albert Garrett in 1911.... [Click to see.] This specimen was later identified as Cirsium scopulorum by Rydberg, and thus began the incorrect usage of this binomial for this species. In 1963, thistle researcher Raymond J. Moore (Canada Department of Agriculture) sent a fragment of the La Sal thistle consisting of a single head and leaf to Arthur Cronquist, curator at the New York Botanical Garden and a leading expert on the Asteraceae family.... Moore wrote a letter stating “herewith in [is] a piece of the strange Cirsium that I was trying to match with specimens at NY [New York Botanical Garden]...." Cronquist replied to Moore, stating “So far as the head and leaf you sent me are concerned, they are, at least at first sight, very much like the general run of material in our folder of C. scopulorum....” However, Cronquist also stated “If your plant represents a considerable population, one might begin to think of the possibility that it belongs to an undescribed species.... In the present state of knowledge (or lack of knowledge) of Cirsium, this is as far as I can go.” And with that [Ackerfield indicates], the new species was left undescribed for the next 60... [years]. All in all, there was a taxonomic lag time of 112... [years] from the first collection made in 1911 to the recognition of the La Sal thistle as a new species."

The word, "Tukuhnikivatz", is widely accepted as the Southern Paiute word for “place where the sun shines longest” and Ute word for “place where the sun sets last”.

Cirsium tukuhnikivatzicum (La Sal Thistle)
Asteraceae (Sunflower Family)

Montane, subalpine. Woodlands, openings. Summer, fall.
La Sal Mountains, Utah, August 10, 2020.

The La Sal Thistle commonly grows to over 3 feet tall with a very narrow upright posture. Where there is one plant, there almost always are many more. Each plant has several dozen flower heads.

I took the photographs on this page in the very dry summer of 2020; the preceding winter snowfall was near normal. With normal summer rains, this species would be much more robust and would easily flower into September. Ackerfield indicates that Cirsium tukuhnikivatzicum flowers as early as July.

Stems of some plants I examined were red or red striped. Ackerfield indicates that stems are "deep maroon".

Leaves are reduced in size upward on the stem.

Flower heads can be single or in groups of two, three, or four.

Cirsium tukuhnikivatzicum (La Sal Thistle)
Asteraceae (Sunflower Family)

Montane, subalpine. Woodlands, openings. Summer, fall.
La Sal Mountains, Utah, August 10, 2020.

According to Ackerfield's description, there are a number of morphological details that separate this taxon from various other Cirsium:

Cirsium tukuhnikivatzicum leaves are pubescent at least below and mid-stem leaf bases are sessile to clasping or short-decurrent to 1 cm. (But Ackerfield's detailed description of C. tukuhnikivatzicum indicates that all C. Tukuhnikivatzicum leaves are clasping or short-decurrent).

The outer involucral bracts are entire and they lack a conspicuous, white glutinous dorsal ridge.

Corolla lobes are less than twice as long as the corolla throat. (But Ackerfield's detailed description of C. tukuhnikivatzicum indicates that the throat is 4–9 mm long, and the lobes are 4–8 mm long); involucres are hemispheric, ovoid, or campanulate.

Two other key morphological details that separate this taxon from the various species it has been placed in are the widely spreading spiny tips of the phyllaries and the dense arachnoid to tomentose pubescence.

All of the plants I saw had white florets but florets may be pink according to Ackerfield.

Cirsium tukuhnikivatzicum (La Sal Thistle)
Asteraceae (Sunflower Family)

Montane, subalpine. Woodlands, openings. Summer, fall.
La Sal Mountains, Utah, August 10, 2020.

Six to twelve inch long basal leaves are cut deeply, the spiny leaflets are often cut again, and the mid-rib is prominent white to green-white.