Bidens

  • Authority

    Britton, Nathaniel L. & Millspaugh, Charles F. 1920. The Bahama Flora.

  • Family

    Asteraceae

  • Scientific Name

    Bidens

  • Description

    Description - Annual or perennial herbs, with opposite serrate lobed divided or dissected leaves, or the uppermost alternate, and mostly large heads of both tubular and radiate flowers, or the rays none, or rudimentary. Involucre campanulate or hemispheric, its bracts in 2 series, distinct or slightly united at the base; the outer often foliaceous and much larger than the inner. Receptacle flat or nearly so, chaffy, the chaff subtending the disk-flowers. Rays, when present, neutral, mostly entire, yellow in our species. Disk-flowers perfect, fertile, their corollas tubular, 5-toothed. Anthers entire, or minutely sagittate at the base. Style-branches with short or subulate tips. Achenes flat, quadrangular or nearly terete, cuneate, oblong, or linear. Pappus of 2-6 teeth or subulate awns, upwardly or downwardly barbed or hispid. [Latin, twotoothed, referring to the achenes.] About 75 species of wide geographic distribution. Type species: Bidens tripartitus L.