[6] Trimeresurus gracilis is a small snake with a total length up to 60 cm (24 in).

[6] It is found only in Taiwan, above 2,000 m (6,600 ft) above sea level.

Nôkô, Nanto Co., central Formosa" (Mount Nengkaoshan, Nantou County, Taiwan).

[2] In a study were results that negated a commonly believed inference relating to the close affinity of T. monticola and T. okinawensis, and also suggested a sister relationship between T. okinawensis and T. gracilis.

Phylogenetic relationships revealed in this study suggested that the genus Trimeresurus dispersed into the Ryukyu region at least three times, and that T. flavoviridis and T. tularensis from the central Ryukyus use to be more widespread and diverse in the past surrounding regions.