Genus Bidens belongs to the family Asteraceae and is a diverse genus with around 230 species throughout tropical and warm temperate zones. Despite its broad dissemination, the systematics and taxonomy of Bidens are often described as complex and disorganized. The taxonomic history of the genus is long and complex, with limited knowledge about its phylogenetic and biogeographic background. These plants produce fruits with a variety of fascinating names, including beggarticks, blackjack, burr marigolds, cobbler’s pegs, Spanish needles, stickseeds, tickseeds, and tickseed sunflowers. These species have a unique feature reflected even in their scientific name, Bidens, which comes from the Latin language, meaning “two” and “tooth.” The genus Bidens, which includes plants and shrubs, is associated with the American genus Coreopsis and has spread to numerous maritime islands. They have erect stems and cauline, opposite or whorled leaves with varying leaf blades. The Hawaiian Islands are home to several species, including those at risk of extinction due to limited ranges and the absence of native mammals. Bidens seeds can disperse to new habitats by attaching to clothing, fur, or feathers.