Bidens is a genus of flowering plants in the aster family, Asteraceae. The genus include roughly 230 species which are distributed worldwide. Despite their global distribution, the systematics and taxonomy of the genus has been described as complicated and unorganized. The common names beggarticks, black jack, burr marigolds, cobbler's pegs, Spanish needles, stickseeds, tickseeds and tickseed sunflowers refer to the fruits of the plants, most of which are bristly and barbed. The generic name refers to the same character; Bidens comes from the Latin bi ("two") and dens ("tooth").
Phylogeny, taxonomy and diversity
Despite their global distribution, the systematics and taxonomy of the genus has been described as complicated and unorganized. The genus include roughly 230 species.
Bidens is closely related to the American genus Coreopsis, and the genera are sometimes difficult to tell apart; in addition, neither is monophyletic.
Species
Species include:
- Bidens alba <small>(L.) DC.</small> – romerillo
- Bidens amplectens <small>Sherff</small> – Waianae kokoolau
- Bidens amplissima <small>Greene</small> – Vancouver Island beggarticks
- Bidens aristosa <small>(Michx.) Britt.</small> – bearded beggarticks, long-bracted beggarticks, tickseed sunflower, western tickseed
- Bidens asymmetrica <small>(Levl.) Sherff</small> – Koolau kokoolau, Ko'olau Range beggarticks
- Bidens aurea <small>(Ait.) Sherff</small> – Arizona beggarticks
- Bidens beckii – Beck's water-marigold, Henderson's water-marigold, Oregon water-marigold
- Bidens bidentoides <small>(Nutt.) Britt.</small> – Delmarva beggarticks
- Bidens bigelovii <small>A.Gray</small> – Bigelow's beggarticks
- Bidens bipinnata <small>L.</small> – Spanish needles, hemlock beggarticks, gui zheng cao ()
- Bidens biternata
- Bidens cabopulmensis
- Bidens campylotheca <small>Sch.Bip.</small>– viper beggarticks
- Bidens cernua <small>L.</small> (syn. B. glaucescens <small>Greene</small>) – nodding beggarticks, nodding bur-marigold
- Bidens cervicata <small>Sherff</small> – Kauai beggarticks
- Bidens chippii <small>(M.B.Moss) Mesfin</small>
- Bidens conjuncta <small>Sherff</small> – bog beggarticks
- Bidens connata <small>Muhl. ex Willd.</small> – purplestem beggarticks
- Bidens coronata <small>(L.) Britt.</small> – crowned beggarticks
- Bidens cosmoides <small>(A.Gray) Sherff</small> – cosmosflower beggarticks, poola nui
- Bidens cynapiifolia <small>Kunth</small> – West Indian beggarticks, alfilerillo
- Bidens discoidea <small>(Torr. & A.Gray) Britt.</small> – discoid beggarticks, small beggarticks, swamp beggarticks, few-bracted beggarticks
- Bidens eatonii <small>Fern.</small> – Eaton's beggarticks, bident d'Eaton
- Bidens ferulifolia <small>(Jacq.) DC.</small> – Apache beggarticks, fern-leaved beggarticks
- Bidens forbesii <small>Sherff</small> – coastal bluff beggarticks
- Bidens frondosa <small>L.</small> – devil's beggarticks, devil's pitchfork, devil's bootjack, pitchfork weed, common beggarticks, sticktights. Pitchfork weed (B. frondosa) is considered to be a weed in New Zealand.
- Bidens gardneri <small>Baker</small> – ridge beggarticks
- Bidens hawaiensis <small>A.Gray</small> – Hawaii beggarticks
- Bidens henryi <small>Sherff</small>
- Bidens heterodoxa <small>(Fern.) Fern. & H.St.John</small> – Connecticut beggarticks, bident différent
- Bidens heterosperma <small>Gray</small> – Rocky Mountain beggarticks
- Bidens hillebrandiana <small>(Drake) O.Deg.</small> – seacliff beggarticks
- Bidens hyperborea <small>Greene</small> – estuary beggarticks, coastal beggarticks, northern estuarine beggarticks, seacliff beggarticks
- Bidens laevis <small>(L.) B.S.P.</small> – smooth beggarticks, smooth bur-marigold, larger bur-marigold. Smooth beggarticks (B. laevis) is a common fall flower in the southeastern United States.
- Bidens lemmonii <small>Gray</small> – Lemmon's beggarticks
- Bidens leptocephala <small>Sherff</small> – few-flowered beggarticks
- Bidens leptophylla
- Bidens macrocarpa <small>(Gray) Sherff</small> – large-fruited beggarticks
- Bidens macroptera <small>(Sch.Bip. ex Chiov.) Mesfin</small>
- Bidens mannii <small>T.G.J.Rayner</small>
- Bidens mauiensis (<small>Gray) Sherff</small> – Maui beggarticks
- Bidens maximowicziana
- Bidens menziesii <small>(Gray) Sherff</small> – Mauna Loa beggarticks
- Bidens meyeri <small>V.A.Funk & K.R.Wood</small>
- Bidens micrantha <small>Gaud.</small> – grassland beggarticks
- B. micrantha ssp. kalealaha <small>Nagata & Ganders</small> – Kalealaha beggarticks
- Bidens mitis <small>(Michx.) Sherff</small> – small-fruited beggarticks
- Bidens molokaiensis <small>(Hillebr.) Sherff</small> – Molokai beggarticks, wedge beggarticks
- Bidens ÃÂ multiceps <small>Fassett</small>
- Bidens nudata <small>Brandegee</small> – Cape beggar's tick, Baja tickseed
- Bidens parviflora
- Bidens pachyloma – Meskel Flower
- Bidens pilosa <small>S.F.Blake</small> – hairy beggarticks
- Bidens polylepis <small>S.F.Blake</small>
- Bidens populifolia <small>Sherff</small> – Oahu beggarticks
- Bidens radiata
- Bidens reptans <small>(L.) G.Don</small> – manzanilla trepador
- Bidens sandvicensis <small>Less.</small> – shrubland beggarticks
- Bidens schimperi <small>Sch.Bip.</small>
- Bidens simplicifolia <small>C.H.Wright</small>
- Bidens socorrensis
- Bidens squarrosa <small>Kunth</small>
- Bidens subalternans <small>DC.</small>
- Bidens tenuisecta <small>A.Gray</small> – slim-lobed beggarticks
- Bidens torta <small>Sherff</small> – corkscrew beggarticks
- Bidens trichosperma <small>(Michx.) Britton</small> – crowned beggarticks
- Bidens tripartita <small>L.</small> (syn. B. acuta, B. comosa) – three-lobed beggarticks, three-part beggarticks, leafy-bracted beggarticks, trifid bur-marigold
- Bidens triplinervia <small>Kunth</small>
- B. triplinervia var. macrantha <small>(Wedd.) Sherff</small>
- Bidens valida <small>Sherff</small> – Mt. Kahili beggarticks
- Bidens vulgata <small>Greene</small> – big devil's beggarticks, tall beggarticks, tall bur-marigold, western sticktight
- Bidens wiebkei <small>Sherff</small> – Wiebke's beggarticks
Formerly placed here
Distribution
Bidens includes roughly 230 species which are distributed worldwide throughout many tropical and warm temperate regions. Species occur in the Americas, Africa, Polynesia, Europe and Asia.
Bidens are zoochorous; their seeds will stick to clothing, fur or feathers, and be carried to new habitat. This has enabled them to colonize a wide range, including many oceanic islands. Some of these species occur only in a very restricted range and several are now threatened with extinction, notably in the Hawaiian Islands. Due to the absence of native mammals on these islands, some of the oceanic island taxa have reduced burrs, evolving features that seem to aid in dispersal by the wind instead.
Human use and interactions
Nodding beggarticks (B. cernua) and hairy beggarticks (B. pilosa) are useful as honey plants. Several Bidens species are used as food by the caterpillars of certain Lepidoptera, such as the noctulian moth Hypercompe hambletoni and the brush-footed butterfly Vanessa cardui, the painted lady.
The Bidens mottle virus, a plant pathogen, was first isolated from B. pilosa, and it infects many other Asteraceae and plants of other families.
Native Hawaiians drink a special tea out of their leaves (known collectively as koûokoûolau) back when they were abundant in Hawaii.
Photo gallery
References
External links