Cirsium vulgare

Morphological description

Biennial or perennial herbaceous plant, with height varying between 50 and 130 cm, but under some conditions it can also reach 200-300 cm. The habit is erect, with angular and branched stems, characterized by spiny wings along the lateral veins. The stem is pubescent, provided with a large central pith, and presents spreading prickles about 3 mm long on the surfaces.

The leaves are alternate, sessile and decurrent along the entire internode; the basal ones gather in a rosette and can measure from 7-10 cm in width up to 20-30 cm in length. The leaves have a shape from oblong-lanceolate to obovate, deeply pinnatifid or pinnatisect, with strongly serrated margins and spiny points (2-15 mm). The upper surface is green, often glabrous or slightly silky, while the lower surface is tomentose or gray-tomentose. The leaf segments are acutely spiny, with the presence of spines both on the main lobes and on the smaller margins. Bracteal leaves are absent.

The inflorescence consists of solitary capitula or grouped in small clusters of 2-3 at the apex of the branches. The capitula are subsessile, ovoid-pyriform in shape, with a diameter of about 2.4-5 cm. The involucre is composed of several series of bracts (10-12), arranged imbricately, lanceolate or linear, with spiny apices (2-8 mm), and often with a tomentose outer surface or covered by arachnoid hairs. The outer bracts have a keeled back.

The flowers are all tubular, hermaphroditic, purplish-pink or violet in color (rarely white), with a pentamerous corolla and slightly zygomorphic symmetry. The corolla measures about 25-40 mm, with a tube 18-25 mm long and lobes 5-7 mm. The stamens are five, protruding from the corolla, with papillose filaments and bifid stigma. Each capitulum can contain up to 200 flowers.

The fruit is an obovate cypsela, 3-4 mm long, with a light surface and darker vertical stripes. It is topped by a plumose pappus of setose hairs 20-30 mm long, connate at the base, which facilitates anemochorous dispersal. The root system is a robust taproot, rich in inulin.

Habitat and distribution

This species is widely distributed in Italy and the Mediterranean basin, with a subcosmopolitan distribution extending also to many other temperate regions of the world. It grows mainly in anthropized and disturbed environments such as uncultivated lands, ditch margins, road and path edges, embankment areas, and abandoned soils.

It prefers well-drained soils, often calcareous or clayey, with predominantly sunny or partially shaded exposure. It is found from the plains up to mountain elevations of about 2000 meters, adapting to various climatic conditions, from hills to subalpine zones.

Flowering period

The flowering period mainly extends from June to October, with peak times in the summer months. In some areas and milder climatic conditions it may start as early as May and continue until October, while at higher altitudes flowering is concentrated in the warmer months. The flowering duration is quite prolonged, favoring the continuous presence of flowers for pollination.

Ecology and pollination

The species reproduces by entomogamy, with pollination carried out by a wide range of pollinating insects. During flowering it is visited by bees, bumblebees, wasps, flies, butterflies (such as Zigaena) and even spiders, which contribute to the fertilization of the flowers.

Seed dispersal occurs mainly by wind (anemochory), thanks to the plumose pappus that facilitates transport even over considerable distances. The plant is adapted to rapidly colonize disturbed environments, exploiting its biennial biology and the ability to produce numerous seeds.

Curiosities and traditional uses

The common name "Bull Thistle" derives from the fact that the young parts of the plant are particularly appreciated as food by donkeys and horses.

Despite its spines, the plant is edible after removing the spines: leaves, stems and capitula can be consumed in cooking, cooked similarly to cultivated artichokes. The leaves and stems are usually boiled or blanched and can be fried after being breaded. The capitula can be cooked like artichokes, offering a milder flavor compared to cultivated thistles.

The roots are rich in inulin, a prebiotic substance, but their food use is discouraged due to the bitter taste and difficulty of preparation.

Traditionally, the inner fiber of the stem was used for paper production, while oil can be extracted from the seeds for local use.

Historically, the scientific name recalls an ancient belief about the therapeutic properties of the roots, considered effective for the treatment of varicose veins.

Etymology

The genus name derives from the Greek "kírsion", meaning "thistle", itself from "kirsós" indicating a varicose vein or swelling of veins. This name refers to the traditional medicinal use of the plant's roots to treat varicose veins.

The specific name "vulgare" derives from the Latin "vulgus", meaning "common people", "common", indicating the wide distribution and frequency of the species.

The Italian common name "Bull Thistle" refers to the appreciation of the plant by donkeys and other pack animals, which willingly consume the young parts of the plant not yet spiny.

Sources

• Prof. S. Pignatti, "Flora d'Italia"
• Acta Plantarum - Flora delle regioni italiane (sheet by Roberta Alberti)
• Tela Botanica / H. Coste, "Flore descriptive et illustrée de la France"
• World Flora Online (WFO)