Onopordum, or cottonthistle,[3] is a genus of plants in the tribe Cardueae within the family Asteraceae.[4] They are native to southern Europe, northern Africa, the Canary Islands, the Caucasus, and southwest and central Asia. They grow on disturbed land, roadsides, arable land and pastures.[5]
They are biennials (rarely short-lived perennials) with branched, spinose winged stems, growing 0.5–3 m tall. In the first season they form a basal rosette of gray-green felted leaves and rarely a few flower heads. In the second season they grow rapidly to their final height, flowering extensively, and then die off after seed maturation.[6]
The leaves are dentate or shallowly lobed to compound with several pinnatifid or deeply cut leaflets, and strongly spiny. The terminal flower head is typical for thistles, a semi-spherical to ovoid capitulum with purple (seldom white or pink) disc florets. There are no ray florets. The receptacle is glabrous with dentate margins. The tube of the corolla is slender, sac-shaped and symmetrical. The anthers have awl-shaped outgrowths on the top. The capitula have several overlapping rows of leathery basal simple linear-lanceolate spines. These are smooth to slightly pubescent.
These plants propagate only by seed. The seed heads mature in mid-summer, releasing their seeds. The fruit is a glabrous achene, 4–6 mm long and with 4-50 ribs. The pappus consists of many rows of simple, fine to minutely rough hairs, united in a circular base.[6]
Onopordum species are used as food plants by the larvae of some Lepidoptera species including Coleophora onopordiella (feeds exclusively on O. acanthium).
In the Greek island of Crete a native species called agriagginara (αγριαγγινάρα) or koufoti (κουφωτοί) has its heads (flowers) and tender leaves eaten raw by the locals.[7]
Some species of Onopordum have been introduced as ornamental plants in the temperate regions of North America and Australia, where they have become naturalised in the wild. In most of these countries, these thistles are considered noxious weeds, especially in Australia where a biological control program has been set up (using the Rosette Crown Weevil, Trichosirocalus briesei).[8] In North America, there are also Trichosirocalus control programs, but they have proved detrimental to native thistles.[9]
Cotton thistle (Onopordum acanthium) from Thomé Flora von Deutschland, Österreich und der Schweiz 1885 Onopordum, or cottonthistle, is a genus of plants in the tribe Cardueae within the family Asteraceae. They are native to southern Europe, northern Africa, the Canary Islands, the Caucasus, and southwest and central Asia. They grow on disturbed land, roadsides, arable land and pastures.
They are biennials (rarely short-lived perennials) with branched, spinose winged stems, growing 0.5–3 m tall. In the first season they form a basal rosette of gray-green felted leaves and rarely a few flower heads. In the second season they grow rapidly to their final height, flowering extensively, and then die off after seed maturation.
The leaves are dentate or shallowly lobed to compound with several pinnatifid or deeply cut leaflets, and strongly spiny. The terminal flower head is typical for thistles, a semi-spherical to ovoid capitulum with purple (seldom white or pink) disc florets. There are no ray florets. The receptacle is glabrous with dentate margins. The tube of the corolla is slender, sac-shaped and symmetrical. The anthers have awl-shaped outgrowths on the top. The capitula have several overlapping rows of leathery basal simple linear-lanceolate spines. These are smooth to slightly pubescent.
These plants propagate only by seed. The seed heads mature in mid-summer, releasing their seeds. The fruit is a glabrous achene, 4–6 mm long and with 4-50 ribs. The pappus consists of many rows of simple, fine to minutely rough hairs, united in a circular base.
Onopordum species are used as food plants by the larvae of some Lepidoptera species including Coleophora onopordiella (feeds exclusively on O. acanthium).
In the Greek island of Crete a native species called agriagginara (αγριαγγινάρα) or koufoti (κουφωτοί) has its heads (flowers) and tender leaves eaten raw by the locals.
Species Onopordum acanthium L. - Cotton thistle, Scotch thistle, Scotch common-thistle, heraldic thistle, woolly thistle
Onopordum acanthium - habit - widespread across Europe and temperate Asia Onopordum acaulon L. - Stemless thistle, horse thistle - France, Spain, Algeria, Morocco, Tunisia Onopordum alexandrinum Boiss. - Egypt, Palestine, Lebanon, Syria, Israel, Jordan Onopordum algeriense (Munby) Pomel - Algeria Onopordum ambiguum Fresen. - Egypt, Palestine, Lebanon, Syria, Israel, Jordan Onopordum anatolicum (Boiss.) Eig. - Turkey Onopordum arenarium M.Hossain & M.A.A.Al-Sarraf - Algeria, Morocco, Tunisia, Libya Onopordum armenum Grossh. - Caucasus, Iran, Turkey Onopordum blancheanum (Eig) Danin - Israel, Palestine, Jordan, Syria, Lebanon Onopordum boissierianum Raab-Straube & Greuter - Turkey Onopordum bracteatum Boiss. & Heldr. - Greece, Turkey, Cyprus Onopordum canum Eig - Iran, Jordan, Israel, Turkey Onopordum carduchorum Bornm. & Beauverd - Lebanon, Syria, Turkey, Iran Onopordum carduelium Bolle - Canary Islands Onopordum carduiforme Boiss. - Egypt, Palestine, Lebanon, Syria, Israel, Jordan Onopordum carmanicum (Bornm.) Bornm. - Iran Onopordum caulescens d'Urv. - Greece Onopordum cinereum Grossh. - Caucasus, Turkey, Iran, Turkmenistan, Afghanistan Onopordum corymbosum Willk. - France, Spain Onopordum cynarocephalum Boiss. & Blanche - Palestine, Lebanon, Syria, Israel, Jordan Onopordum cyrenaicum Maire & Weiller - Libya Onopordum dissectum Murb. - Spain, Morocco Onopordum dyris Maire - Morocco Onopordum elongatum Lam. Onopordum eriocephalum Rouy - France Onopordum espinae Coss. Onopordum heteracanthum C.A.Mey. - Caucasus, Lebanon, Turkey, Syria, Palestine, Iran, Afghanistan, Saudi Arabia Onopordum horridum Viv. - Italy Onopordum illyricum L. - Illyrian thistle, Illyrian cottonthistle - Mediterranean Onopordum leptolepis DC. - from Palestine to Altay + Xinjiang Onopordum macracanthum Schousb. - Spain, Portugal, Italy, Morocco, Algeria Onopordum macrocanthum d'Urv. Onopordum macrocephalum Eig - Palestine, Lebanon, Syria, Israel, Jordan Onopordum mesatlanticum Emb. & Maire - Morocco Onopordum micropterum Pau - Spain, Canary Islands Onopordum minor L. - Iran Onopordum myriacanthum Boiss. - Greece, Turkey, Bulgaria Onopordum nervosum Boiss. - Moor's cottonthistle - Spain, Portugal Onopordum parnassicum Boiss. & Heldr. - Greece, Turkey Onopordum platylepis (Coss. ex Murb.) Murb. - Libya, Tunisia Onopordum polycephalum Boiss. - Turkey Onopordum prjachinii Tamamsch. - Uzbekistan, Kyrgyzstan, Tajikistan Onopordum seravschanicum Tamamsch. - Uzbekistan, Kyrgyzstan, Tajikistan Onopordum sibthorpianum Boiss. & Heldr. - Greece, Sicily, Malta, Turkey, North Macedonia, Saudi Arabia Onopordum tauricum Willd. - Turkish thistle, Taurian thistle, Taurus cottonthistle, bull cottonthistle - southern + central Europe, Ukraine, Middle East Onopordum turcicum Danin - Turkey Onopordum wallianum Maire - Morocco Natural hybrids Onopordum × brevicaule (Onopordum acaulon × Onopordum acanthium ) Onopordum × erectum (Onopordum nervosum ssp. castellanum × Onopordum tauricum ssp. corymbosum ) Onopordum × macronervosum (Onopordum nervosum × Onopordum macrocanthum) Onopordum × onubense (Onopordum dissectum × Onopordum macrocanthum) Onopordum × spinosissimum (Onopordum illyricum × Onopordum acanthium)
