Tropidolaemus was established by German physician and zoologist Johann Georg Wagler in 1830 but subsequent workers preferred that it be maintained under the genus Trimeresurus. In my youth, I have recurrently consulted Dr. Alcala’s Guide to Philippine Flora and Fauna, where both T. subannulatus and T. philippensis are referred to as Trimeresurus wagleri, a treatment in line with Leviton’s view, as detailed in the latter’s 2014 book, “The Dangerously Venomous Snakes of the Philippine Archieplago with Identification Keys and Species Accounts”. In 1996, Kraus, Mink, and Brown resurrected the genus, a line of thought still followed to this day. Tropidolaemus differs significantly from members of the latter genus by its strongly keeled gular (throat) scales, small and keeled scales on the head, absence of a nasal pore, and a hemipenis that is actually closer to terrestrial pit vipers (Calloselasma, Deinagkistrodon, and Hypnale) than it is to other arboreal vipers. The specimen used to describe the species was collected by the Englishman Hugh Cuming, who also collected great numbers of shells as well as plants from the Philippines from 1836 to 1850, and which were later described as new species; Cuming did not designate a specific locality for his specimens, choosing instead to label these as simply from the “Philippines”. The species was formerly described as Trimesurus subannulatus by John Edward Gary in 1842. In 1864, Albert Karl Ludwig Gotthilf Günther placed the taxon in the synonymy of Trimeresurus wagleri -- a decision which was followed by many subsequent authors and which stood for many decades. As mentioned above, the populations from Negros differs from what is perceived as T. subannulatus, an anomaly that was rectified by Edward Taylor when he described Trimeresurus wagleri alboviridis in 1917, based on specimens he collected two years earlier from Isabela, Negros Occidental. In due time, if these animals from that island are granted an autonomous status then these will be referred to as Tropidolaemus alboviridis.