The smooth green snake (Opheodrys vernalis) is a species of North American nonvenomous snake in the family Colubridae. The species is also referred to as the grass snake. It is a slender, "small medium" snake that measures as an adult. It gets its common name from its smooth dorsal scales, as opposed to the rough green snake, which has keeled dorsal scales. The smooth green snake is found in marshes, meadows, open woods, and along stream edges, and is native to regions of Canada, the United States, and northern Mexico. A non-aggressive snake, it seldom bites and usually flees when threatened. It mates in late spring to summer, and females lay their eggs from June to September. Smooth green snakes will often bob their heads in order to mimic vegetation blowing in the wind. Description The smooth green snake is slender. In size, it is classified as a "small medium" snake, reaching to in total length (including tail) as an adult. The longest smooth green snake was measured as being in total length. The tail makes up about 1/4 to 1/2 the total length of the snake; males have longer tails than females. It is uniform light green on its back, with a yellow or white belly, and has smooth dorsal scales, unlike those of the rough green snake, which are keeled. Its smooth dorsal scales are arranged in 15 rows at midbody. At birth, its dorsal coloration is different from that when it matures. At first, it can be olive green, blue-gray, or even brown, but after it sheds its skin for the first time, it becomes the characteristic bright green. The dorsal coloration can also vary depending on location: bluish in Kansas, olive-tinted light brown in southeastern Texas, and bronze in northern Wisconsin. It uses its tongue, red with a black end, by flicking it in and out of its mouth to "smell" what is around it. Subspecies Eastern smooth green snake, Opheodrys vernalis vernalis (Harlan, 1827) Western smooth green snake, Opheodrys vernalis blanchardi Grobman, 1941 Northern smooth green snake, Opheodrys vernalis borealis Grobman, 1992 Etymology The subspecific name, blanchardi, is in honor of American herpetologist Frank N. Blanchard. Geographic range The smooth green snake is native to the Nearctic region. The range spreads through southeastern Canada, west to Saskatchewan, and south through Illinois and Virginia. It can also be found in other areas, such as in Wyoming,