Bidens

Strahliger Bidens ( Bidens radiatus )

The two teeth ( Biden ) are a genus of flowering plants in the sunflower family ( Asteraceae).

6.1 Literature
6.2 Notes and references
6.3 External links

Description

In Bidens species are annual to perennial herbaceous plants. The leaves are opposite, which is rather unusual for the daisy family. Only the uppermost leaves are also alternate in some species. The leaves can be feathered, be pinnatisect or undivided. In the latter case they are then at least cut.

The bloom conditions of most species consist of tubular florets and ray florets, in other species, however, the ray florets are formed only rudimentary or absent. In this case, the flowers are often surrounded by bract -like leaves. The flowers are usually yellow, but also species with white, red or pink ray florets before coming. Between the tubular flowers are chaff leaves in the plant species of this genus.

Their name from the two teeth the teeth by their fruits. Namely, the pappus is reduced to two to six often bristle-like teeth with them. These are often busy with looking back hook bristles so that they can easily get stuck in the fur of animals or clothing. In some species the teeth are branched feathery, while others, especially the Inselendemiten, missing the hook bristles. The presence of these teeth bordering the pretty diverse genus well as against other genres.

Dissemination

The genus Bidens is distributed worldwide ( except Antarctica ). Of the approximately 250 species, most occur in the Americas and in Africa. Approximately 60 species are restricted to Polynesia, where it in turn 40 in Hawaii are endemic. In Germany, five species occur, of which two were introduced.

System

Taxonomy

The genus Bidens was erected in 1753 by Carolus Linnaeus in Species Plantarum. According to the International Code of Nomenclature for algae, fungi, and plants, Article 62.2, the grammatical gender must conform to the last part of the name for compound names, with " Bidens " ie, after the masculine Latin " dens ". Because Linnaeus but was the generic name used mostly feminine in later literature in agreement with previous authors feminine cars, and the name, 1998, a preservation request was made to determine the gender of the name Bidens on feminine. The acceptance of this proposal was first recommended in 2000 by the Nomenclature Committee for Spermatophyta, but you submitted for a fresh assessment in the light of new findings again in 2006. As long as this new recommendation is not made public and no International Botanical Congress voted on that request, the grammatical gender of Bidens masculine with correct application of the rules of nomenclature.