Common names: black-speckled palm-pit viper, speckled palm viper, more. Bothriechis nigroviridis is a venomous pit viper species found in the mountains of Costa Rica and Panama. No subspecies are currently recognized. The specific name is derived from the Latin nigro (black) and viridis (green) in reference to its distinctive color pattern.
Adults may exceed 80 centimetres (31 in), although most are less than 60 centimetres (24 in) in length. They are relatively slender and have a prehensile tail. Two exceptionally large females were reported by Hammack and Antonio (1991) that measured 89.2 centimetres (35.1 in) and 93.7 centimetres (36.9 in).
The color pattern usually consists of an emerald green (rarely yellowish green) ground color with strong black mottling. There may also be pale green dorsal blotches that have black edges. The belly is yellowish green and lightly mottled with black. The head is heavily mottled with black on top, often with black parietal stripes. There is also a clearly defined postocular stripe running back towards the angle of the jaw. The iris is heavily stippled and appears almost black. The tongue is also black. Juveniles have a similar color pattern, although it is more pale and the tip of the tail is black.