Two teeth

Two teeth
Radial two-tooth ( Bidens radiatus )
Systematics
Euasterids II Order : Astern-like (Asterales) Family : Daisy family (Asteraceae) Subfamily : Asteroideae Tribe : Coreopsideae Genre : Two teeth
Scientific name
Bidens
L.

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

Description and ecology

Illustration from Storm of the Nodding Two Tooth ( Bidens cernua )

Infructescence of the black fruit two-toothed tooth ( Bidens frondosus ) with the typical cusps and the two bristles on the achenes

Bidens gardneri flower head

Vegetative characteristics

When Biden TYPES comes to annual to perennial herbaceous plants .

The leaves are opposite , which is rather unusual for the daisy family. Only the top leaves are alternate in some species . The leaf blades can be pinnate, pinnate or undivided. In the latter case they are at least sawn.

Generative characteristics

The cup-shaped inflorescences of most species consist of tubular flowers and ray - florets , in other species, however, the ray - florets are only rudimentary or absent. In this case, the flowers are often surrounded by bract-like leaves. The flowers are mostly yellowish, but there are also species with white, reddish or pink ray florets. In the plant species of this genus, there are chaff leaves between the tubular flowers .

The two teeth owe their name to the teeth on their fruits. The papus is reduced to two to six often bristle-shaped teeth. These are often covered with hooked bristles pointing back, so that they can easily get caught in the fur of animals or in clothing. In some species the teeth are branched like a feather, in others, especially the island endings , the hook bristles are missing. The presence of these teeth clearly distinguishes the very diverse genus from other genera.

Bidens albus

Bidens aristosus

Illustration by Bidens beckii

Leaved bipod ( Bidens bipinnatus )

Bidens campylotheca

Bidens hillebrandianus

Bidens mauiensis , endemic to Maui, Hawaii

Bidens menziesii

Bidens micranthus

Bidens tortus

Systematics and distribution

Taxonomy

The genus Bidens was in 1753 by Linnaeus in Species Plantarum erected . According to the International Code of Nomenclature for algae, fungi, and plants , Article 62.2, the grammatical gender of compound names must be based on the last component of the name, in the case of "Bidens" that is, the masculine Latin word "dens". Because Linnaeus used the generic name feminine in accordance with earlier authors, and the name was also mostly used feminine in later literature, an application for preservation was made in 1998 to determine the gender of the name Bidens to feminine. The acceptance of this application was initially recommended in 2000 by the Nomenclature Commission for Spermatophytes, but was submitted to it again in 2006 for renewed assessment in the light of new findings. As long as this new recommendation has not been published and no International Botanical Congress has voted on this proposal, the grammatical gender of Bidens is masculine if the nomenclature rules are correctly applied. According to the ICBN rules , the epithet of the type ending with “... a” must then be changed to “... us”.

External system

The genus Bidens belongs to the tribe Coreopsideae in the subfamily Asteroideae within the family of Asteraceae .

Species and their distribution

The genus Bidens is distributed worldwide (except in the Antarctic). Most of the approximately 250 species are found in the New World and Africa. About 60 species are restricted to Polynesia , of which 40 are endemic to Hawaii . There are five species in Germany, two of which were introduced.

Here is a selection of around 250 species:

• Bidens albus (L.) DC. : It is distributed in Florida and from Mexico through Central and South America.
• Bidens amplissimus Greene : It occurs in western North America only in British Columbia and Washington .
• Bidens aristosus (Michx.) Britton : It occurs in the eastern and central United States.
• Gold two-toothed tooth ( Bidens aureus (Aiton) Sherff ; Syn .: Bidens heterophyllus Ortega ): It occurs in Arizona , Mexico and Guatemala .
• Bidens beckii Torr. ex Sprengel : This aquatic plant is common in North America in Canada and in the United States.
• Bidens bidentoides (Nuttall) Britton : It thrives on river banks in the US states of Delaware , Maryland , New Jersey , New York and Pennsylvania .
• Bidens bigelovii A.Gray : It occurs in the US states of Arizona, Colorado , Oklahoma , New Mexico , Texas and Mexico.
• Fiederblättriger Bidens ( Bidens bipinnatus L. ): It is distributed in North America in Canada and the United States.
• Bidens biternatus (Lour.) Merr. & Sherff : It is common in Asia, Africa, New Caledonia and the Solomon Islands and is a neophyte in Europe.
• Bidens campylotheca Sch. Gdp. : It only occurs in Hawaii .
• Nodding two-toothed tooth ( Bidens cernuus L. ): It is common in Eurasia and North America.
• Overgrown two-toothed tooth ( Bidens connatus Willd. ): It is common in North America. According to the Flora of North America , this species should better be associated with Bidens tripartitus , this is controversial.
• Bidens cynapiifolius Kunth : It occurs in Mexico only in the Yucatan , on many Caribbean islands and in South America.
• Bidens discoideus (Torrey & A.Gray) Britton : It is found in eastern Canada and the eastern and southeastern United States.
• Bidens eatonii Fernald : It is found in eastern Canada and the northeastern United States.
• Goldmarie or Ferula-Zweizahn ( Bidens ferulifolius (Jacq.) DC. ): The home is Arizona and Mexico.
• Bidens frondosa ( Bidens frondosus L. , syn .: Bidens melanocarpus Wiegand ): The home is Alaska, Canada and the United States. In addition, the species occurs in Europe, Asia, Morocco and New Zealand as a neophyte.
• Bidens heterodoxus (Fernald) Fernald & H.St.John : It occurs in eastern Canada and in the US state Connecticut .
• Bidens heterospermus A.Gray : It thrives at altitudes of 1,500 to 2,800 meters in the US states of Arizona, New Mexico, Colorado and Mexico.
• Bidens hillebrandianus (Drake) O.Deg. ex Sherff : It occurs in two subspecies only in Hawaii:
  • Bidens hillebrandianus subsp. hillebrandianus
  • Bidens hillebrandianus subsp. polycephalus Nagata & Ganders : It occurs on Molokai and Maui.
• Bidens hyperboreus Greene : It is found in Canada and the northeastern United States.
• Bidens laevis (L.) Britton, Sterns & Poggenburg . It is widespread from North to Central to South America and is a neophyte in Hawaii.
• Bidens lemmonii A.Gray : It thrives at altitudes of 1,300 to 2,100 meters in the US states of Arizona and New Mexico and also in Mexico.
• Bidens leptocephalus Sherff : It occurs in the US states of Arizona, New Mexico as well as Texas and Mexico.
• Bidens leptophyllus C.H. An : It is only found in Xinjiang .
• Bidens mathewsii Sherff : She is an endemic to Pitcairn .
• Bidens mauiensis (A.Gray) Sherff : It occurs in Hawaii.
• Bidens maximowiczianus Oettingen : It occurs in China, Japan, Korea and Russia.
• Bidens micranthus Gaudich. : It occurs in three subspecies in Hawaii:
  • Bidens micranthus subsp. ctenophyllus (Sherff) Nagata & Ganders
  • Bidens micranthus subsp. kalealaha Nagata & Ganders : It occurs on Maui and Lanai.
  • Bidens micranthus subsp. micranthus
• Bidens mitis (Michx.) Sherff : It occurs in the US states of Texas, Alabama , Delaware , Florida, Georgia , Louisiana , Maryland , Mississippi , North Carolina , South Carolina and Virginia .
• Bidens molokaiensis (Hillebr.) Sherff (Syn .: Bidens cuneatus Sherff ): The home is Hawaii.
• Bidens parviflorus Willdenow : It occurs in China, Japan , Korea , Mongolia and Russia.
• Hairy two-toothed tooth ( Bidens pilosus L. ): It is a pantropically widespread species. The home ranges from California to Mexico, the Caribbean islands, and Central to South America.
• Bidens polylepis S.F. Blake : It is common in Canada and the United States.
• Radiant two-tooth or radiant two-tooth ( Bidens radiatus Thuill. ): It is common in Eurasia.
• Bidens riparius Kunth : It is distributed from Mexico to Central and South America.
• Bidens squarrosus Kunth : It is distributed from Mexico to Central and South America.
• Rio Grande Two Tooth ( Bidens subalternans DC. ): The home is Cuba and South America.
• Bidens tenuisectus A. Gray : It occurs in the US states of Arizona, Colorado, Idaho , New Mexico, Utah and in the Mexican state of Chihuahua .
• Bidens trichospermus (Michx.) Britton (Syn .: Bidens coronatus (L.) Britton ): Home is Canada and the United States.
• Three-part two-tooth ( Bidens tripartitus L. , Syn .: Bidens comosus (A.Gray) Wiegand): It is widespread in Eurasia, North Africa and North America. It is a neophyte in many areas of the world. According to the Flora of North America , this species should contain several other species, this is still controversial.
• Three-veined two-toothed tooth ( Bidens triplinervius Kunth ; including Bidens humilis Kunth ): It is distributed from Mexico to Central and South America.
• Bidens vulgatus Greene : It is native to Canada and the United States, in southern Europe it is a neophyte.
• Bidens wiebkei Sherff : The home is Hawaii.

The gold marie ( Bidens ferulifolius ) is used as an ornamental plant for window boxes and planters

use

Some of the less Bidens species are ornamental plants , for example the golden marie ( Bidens ferulifolius ).

swell

Individual evidence

1. ↑ ^{a b c d e f g h i j k l m n o p q r s} John L. Strother, Ronald R. Weedon: In: Flora of North America Editorial Committee (ed.): Flora of North America North of Mexico , Volume 21, New York and Oxford 2006. Bidens Linnaeus. - online with the same text as the printed work.
2. ↑ ^{a b c d e f} Yousheng Chen, DJ Nicholas Hind: Heliantheae. : Bidens Linnaeus. Text same online as printed work , In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China. Volume 20-21: Asteraceae. Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 2011, ISBN 978-1-935641-07-0 .
3. ^ ^{A b} Carl von Linné: Species Plantarum. Volume 2, Lars Salvius, Stockholm 1753, p. 831, digitizedhttp: //vorlage_digitalisat.test/1%3Dhttp%3A%2F%2Fwww.biodiversitylibrary.org%2Fopenurl%3Fpid%3Dtitle%3A669%26volume%3D2%26issue%3D%26spage%3D831%26date%3D1753~GB%3D~ IA% 3D ~ MDZ% 3D% 0A ~ SZ% 3D ~ double-sided% 3D ~ LT% 3D ~ PUR% 3D
4. ↑ John McNeill, FR Barrie, WR Buck, V. Demoulin, Werner Greuter, DL Hawksworth, PS Herendeen, Sandra Knapp, Karol Marhold, J. Prado, WF Prud'homme Van Reine, Gideon F. Smith, JH Wiersema, Nicholas J Turland: International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) (= Regnum Vegetabile. 154). ARG Gantner, Ruggell 2012, ISBN 978-3-87429-425-6 , Art. 62.2 online.
5. ^ Neil A. Harriman (1357) Proposal to conserve the name Bidens (Asteraceae) with a conserved gender. In: Taxon. Volume 47, No. 2, 1998, pp. 485-486, JSTOR 1223797 .
6. ^ RK Brummitt: Report of the Nomenclature Committee for Vascular Plants: 49. In: Taxon. Volume 49, No. 2, 2000, pp. 261-278 (here: p. 272), JSTOR 1223840 .
7. ^ Fred R. Barrie: Report of the General Committee: 9. In: Taxon. Volume 55, No. 3, 2006, pp. 795-800 (here: pp. 796-797), JSTOR 25065657 .
8. ↑ ^{a b c d e f g h i j k l m n o p q r s t u v w x y} Bidens in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.

Web links

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