Cirsium

Cirsium arvense

Cirsium is a genus of spiny herbaceous plants commonly known as thistles, among other common names, of the Asteraceae family. It comprises more than 2,850 described specific and infraspecific taxa and, of these, only about 550 accepted.

Description

They are spiny annual or perennial herbaceous plants that can reach up to 4 m in height. The stems are simple or branched, sometimes with spiny wings. The leaves are 1-3 pinnate, glabrous or densely tomentose. The heads can be solitary or well organized in clusters, spikes, panicles or corymbs. The ovoid/spherical involucre is 1 to 8 cm long, with bracts in 5-20 rows, erect and usually with a spiny apex, except the internal ones. In many species they have resin glands. The receptacle is flat or convex, very scaly. The florets range from white to purple, through pink, red or yellow. They have long and thin tubes. The fruits are smooth and glabrous (cypselae) with a persistent or deciduous pappus in 3-5 series of numerous flattened, feathery or toothed bristles, united at the base in a ring.

Distribution

Cosmopolitan. The genus has few native representatives in North America, where species introduced from Eurasia are a pest in many areas. It occupies absolutely all habitats, from jungle to desert, and from beaches to high mountains and from the tropics to boreal latitudes.

Taxonomy

The genus was created and first described in The Gardeners Dictionary,(ed. 4), p. 334 in 1754 by Philip Miller. The type species is: Cirsium heterophyllum (L.) Mill., whose basionym is Carduus heterophyllus L., 1753 and with the lectotype designated by Nathaniel Lord Britton Addison Brown in An Illustrated Flora of the Northern United States, ed. 2, 3, no. 104, p. 548[1], 1913.

Etymology

Cirsium: generic name derived from the Latin word cirsĭŏn, -ĭi —from the Greek χιρσός, -ον, "varicose veins"— a word used by Pliny the Elder (Naturalis Historia, 27, 61) to identify a thistle that is used to treat this type of ailment. In modern times, the French botanist Tournefort (1656 - 1708) has derived the name Cirsium.

Synonyms

Species

Selected species

Complete list of all described specific and infra-specific taxa and their synonymies in The Plant List[2].

Taxa present in Spain

Species and subspecies:

Hybrids: