Grey herbs

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Grey herbs (Senecio), also crucifix herbs (such as "gray herb" originated from , to "gray, old"); Greis" and "leaf plant, foliage, herb") are a plant genus within the family of osiers (Asteraceae). Depending on the author, well over a thousand species are distributed almost worldwide.

Description

Vegetative characteristics
Greis wort species are mostly one- or two-year-old or perennial herbaceous plants, some species wooden and grow as evergreen half-shrubs, shrubs or climbing plants. Depending on the type, they reach heights of 5 to 100, up to more than 250 centimeters. The stems are upright or lying. Some species form rhizomes, very rarely spurs.

The alternately arranged foliage leaves are stalked or seated. The leaf spread can have very different shapes, from thread-like to lancet-like to egg-like, loin-like and from lapped to tongue-split to tongue-particle. The blade edge can be smooth, toothed or sawn. There is a plumage nerve.

Generative characteristics
There is usually a flower basket shaft. Usually, some to many upright or nodding cup-shaped inflorescences are summarized in terminal, simple or composite umbrella grape or umbrella-ripping total inflorescences, rarely are the inflorescences individually. The envelope (involucrum) can be bell-shaped, hemispherical or cylindrical with or without an outer casing. Depending on the species, 5 to 22 leathery to herbaceous wrapping leaves are present, which are usually free from each other; its edge is skinned or dry skinned. The basket floor is flat. The flower baskets are either heterogamous and spherical or homogamous and disc-shaped. The flower baskets contain at the edge 1 to 5, 8, 13 or 21 (rarely 24 to 34) ray flowers = zygomorphic tongue flowers (they can be missing) and inside rarely 3 to 5, usually 13 to more than 80 (many) disk flowers = radiarly symmetrical tube flowers. The crown leaves have grown into a tube. The tongues of the tongue blossoms are usually striking and yellow, rarely tiny, two to nine-strong and usually three-lobed. The yellow tube flowers are funnel-shaped or cylindrical and end with five crown lobes. The dust bags are elongate to linear and usually short blunt-tubed, rarely tailed ±. The two handles are trimmed or less often convex.

The usually five-ribbed or winged Achenes are cylindrical and bald or fluffy haired. The white, straw-colored or reddish-brown pappus is hairy and uniform or rarely dimorphic.

Nomenclature and distribution
The genus Senecio was created by Carl von Linné. The generic botanical name Senecio is derived from the Latin word senex for “grass”, presumably because the fruiting plants are reminiscent of old hair due to the whitish hair crowns of the fruit; Another possibility would be because of the hemispherical and bare basket floors reminiscent of balding heads. As a lectotype species