Mention thistle and immediately the purple thistle that is the floral emblem of Scotland comes to mind. Yet there are several genera of thistles and not all thistles look like the “Scotch” thistle. An artichoke is a thistle.
The dwarf thistle (Cirsium scariosum) is one of my local favorites. A perennial, native to most of Western United States, dwarf thistle is a member of the sunflower family (Asteraceae). This thistle can take three forms – a) flat rosette with flowers in the center, b) short stemmed resembling a mound and c) fully erect. Formerly different forms of this variable thistle were classified as separate species. Currently all the races of dwarf thistle are considered one species.
I think dwarf thistle looks fascinating. Found in sagebrush scrub, dry meadows, and ponderosa and lodgepole pine forests, C. scariosum goes by many common names including elk thistle and meadow thistle. The white to light pink flowers are nestled into the rosette (the form common regionally) of deeply indented, spine-tipped leaves. Often the leaves are covered with cobwebby hairs. Bracts tipped with spines (invoucre) surround the base of the flower. The achene (small, dried seed) is tipped with modified hairs or bristles (pappus) that disperse the seeds in the wind. The pappae of the Cirsium genus are feathered tufts. Dwarf thistle has a large taproot.
Like many other thistles, the tap root and peeled stems of dwarf thistle are edible raw or cooked. I have not tried to eat dwarf thistle since this plant does not have stems and I have not been willing to brave the spines to get at the root. However, it is not difficult (or painful) to cut one of the stemmed thistles and hold it by the base while stripping the outer skin, leaves and spines with a pocket knife. The core of the stem resembles a stalk of celery and has the same crisp texture. I assume the root of dwarf thistle has much the same texture and bland taste as other thistles. The larvae of some butterflies and hummingbirds also use dwarf thistle as food.
Many thistles are extremely aggressive and crowd out other native plants and agricultural crops. Dwarf thistle is less competitive. So although some sources consider it a noxious weed, most list it as a wildflower.
The genus name of dwarf thistle, Cirsium, comes from the Greek for “swollen vein”. Although dwarf thistle itself does not appear to be used to treat swollen veins, other members of the genus were used for that purpose.
These dwarf thistle plants were photographed in the McArthur Swamp (Shasta County CA).