deutsch | english

Flora Emslandia - Plants in Emsland (northwestern Germany)

Carduus, plumeless thistles

Carduus L.: The botanical genus name means both "thistle" and "artichoke" and is handed down in written form for the first time by Vergil (70–19 B.C.). Linnaeus described the genus in 1754 in his Genera plantarum. From the very similar plume thistles (Cirsium), the representatives of Carduus can be distinguished on their pappus. The hairs of the pappus, which are attached to the fruits, are feathery at Cirsium and simple at Carduus.

The genus comprising up to 100 species, which are native to Eurasia and to tropical Africa and introduced in America and Australia. It consists of annual to biannual or perennial herbaceous plants. The upright stems are spiny winged and repeatedly branched or simple. The basal leaves and the stem leaves are spiny toothed and may be almost simple or up to twofold pinnatipartite. The alternate stem leaves are stalked or sessile.

The single standing flowerheads which may also be clustered or arranged in racemose corymbs, containing only tubular flowers that are usually pink or purple. The 5-dentate floral tubes of the hermaphrodite florets are relatively long, sometimes zygomorphous, slim and at the base without chaffy leaves. The flat receptacle is densely covered with spines. The heads are surrounded by a tubular or spherical involucre. The linear or broad-ovate phyllaries are erect, spreading or recurved, mucronate and are arranged scale-like in 6–12 rows.

After the pollination, usually conducted by butterflies, bees and bumblebees, the inferior ovary forms an ovoid, slightly flattened nut fruit (achene) with a simple pappus consisting of 4-5 rows of hairs which are easily removable, rough and connected at the base to form a ring.

Floral formula:

* K=pappus [C(5) A5(connate)] G(2) inferior

Historical publications

Publius Vergilius Maro, called Virgil (70–19 BC), a famous Roman poet, wrote in 42 BC in his fifth eclogue (Daphnis): „Grandia saepe quibus mandavimus hordea sulcis / infelix lolium et steriles nascuntur avenae; / pro molli viola, pro purpurea narcisso / carduus et spinis surgit paliurus acutis.“ (Where we were so often in the furrows confident on large millet / grows ominously ryegrass and barren oats. / Instead of soft violets, instead of violet narcissus / the thistle rises and spiny Christ thorn).

In Pliny (about 23–79 AD.) often falls the term Carduus for acanthophyllous plants. What species was exactly meant by that, or whether he summarized several species, can not be longer ascertained exactly.

Meaning of the species names

• polyacanthus: gr. with many spines
• crispus: lat. crispus = curly

Interesting notes

• The place name "Chardonnay" possibly derives from the Latin word Cardonnacum = "place with many thistles".