Species that can occur both in wetlands and uplands; there are three subcategories of facultative species: facultative wetland plants (FACW) that usually occur in wetlands (estimated probability 67-99%), but occasionally are found in nonwetlands, facultative plants (FAC) that are equally likely to occur in wetlands or nonwetlands (estimated probability 34-66%), and facultative upland plants (FACU) that usually occur in nonwetlands (estimated probability 67-99%), but occasionally are found in wetlands (estimated probability (1-33%).