The purpose of this Resource Recovery Plan was to uncover information about a rare tidal marsh species in Pennsylvania, Bidens bidentoides. After compiling and determining its classification, description, ecology, conservation status, and historical populations, the plan shows what needs to be known and done about this species in terms of further research that should be conducted to prevent this species’ extirpation. In addition to compiling the plan that will be submitted to the Pennsylvania Department of Conservation and Natural Resources, three sites where Bidens bidentoides has been found in the past were visited to get a better understanding of its present populations. Also, the 120 specimens of Bidens bidentoides in the PH Herbarium at the Academy of Natural Sciences of Drexel University were imaged and databased. This historical population information will be made available to the public in the near future.