Florida green watersnake (Nerodia floridana) is a harmless North American species of water snake. N. floridana is the largest and most dominant watersnake in North America. Fully grown it will typically reach 76–140 cm (30–55 in), with the record-sized specimen having measured 188 cm (74 in). Its coloration is solid greenish-brownish with whitish belly in adults. Juveniles have about 50 dark bars down their dorsum and on their sides, which fade gradually with age.