Trimeresurus gramineus is a venomous pitviper species found only in southern India. No subspecies are currently recognized. Rostral scale as deep as broad or broader than deep; upper head-scales small, smooth, imbricate; supraocular scale narrow, rarely broken up; internasals in contact or separated by one or two scales; 8 to 13 scales on a line between the supraoculars; usually one or two, rarely three, series of scales between the suboculars and the labials ; 9 to 12 upper labials, second usually forming the anterior border of the loreal pit, third largest; temporal scales smooth. Scales more or less distinctly keeled, in 21 (rarely 19 or 23) rows. Ventrals 145-175; anal scale entire; subcaudals 53-76. Upper parts usually bright green, rarely yellowish, greyish, or purplish brown, with or without black, brown, or reddish spots ; usually a light, white, yellow, or red streak along the outer row of scales ; end of tail frequently yellow or red; lower parts green, yellow, or whitish. Grows to a length of 2.5 feet (0.76 m); tail 6-5 inches.
