Conyza

Canadian fleabane

The profession herbs ( Conyza ) are a genus of flowering plants from the sunflower family ( Asteraceae). It has been just like the closely related genus Erigeron named " Occupation herbs" is in German. A systematic point of Conyza has often been incorporated into the genus Erigeron; to distinguish the German name Conyza is also called cat 's tail; for Erigeron is also the name " Fine Focus " usable. The genus Conyza, with about 60 species in the temperate and warmer regions, especially America's widespread.

Features

Conyza are annual to perennial herbaceous plants, rarely shrubs or small trees. The alternate leaves are usually standing lanceolate, entire to toothed or lobed feathery.

Add or umbrella-shaped inflorescences aged men rather small basket- shaped part inflorescences are up to several together very numerous, rarely only a single flower head is available. The basket bottom is flat to slightly domed and usually naked. The involucre is bell - shaped to urn. The bracts are available in two to four rows, more or less overlapping, rarely herbaceous and soon distanced far. The ray florets are numerous, their crown very narrow. You are female, and are available in several rows. Her crown is tube- to filiform. The tubular flowers are hermaphrodite, or functionally male.

In contrast to the genus profession herbs ( Erigeron ) the ray florets are here very short and the cups have only a diameter of a few millimeters. The color of ray florets is usually whitish, but they can also be yellow or purple. The tubular flowers are hermaphrodite or sometimes functionally male, usually a few, tubular flowers with ( four or ) five lobes.

The achenes are verkehrteiförmig to oblong, sometimes compressed, usually hairy. The pappus consists of many fine, fragile bristles.

Differences between Conyza and Erigeron

The distinguishing features between the two as a professional herbal designated genera are not always clear. Normally, Conyza unbalanced Involucralblätter and two to 20 times as many female as hermaphrodite flowers in each head, rarely more than female hermaphrodite. The crown of the female flowers usually have no tongue, or at least this is less than one millimeter. The genus Erigeron has approximately symmetrical Involucralblätter and more androgynous than female flowers. The crown of the female flowers usually has a tongue of two to ten millimeters.

Dissemination

The genus Conyza is mainly tropical and subtropical widespread, both in the Old and New World.

Types (selection)

There are, depending on the source of 25 to 60 species. After molecular biological investigations, the genus should be classified in the genus Erigeron. Conyza itself is likely to be polyphyletic, at least paraphyletic

In Europe, three species have been introduced ( neophytes ):

• Canadian fleabane ( Conyza canadensis ) ( widely used type )
• South American fleabane ( Conyza bonariensis ) (often naturalized in the Mediterranean region, rarely also in Central Europe. )
• Whitish fleabane ( Conyza sumatrensis ) (often naturalized in the Mediterranean region, and increasingly in Central Europe. )

Swell

• Entry in the Flora of North America. (English)
• Entry in the Digital Flora of Taiwan.

Single References