We discovered new populations of Dendragama at the northern and southern ends of Sumatra. High genetic distances and concordance of multiple, apparently independent diagnostic characters support our descriptions of these two populations as new species. We define new characters of the sublabial, tympanic, dorsal crest, and dorsolateral crest scales. The three species of Dendragama undergo remarkable color change in response to time of day and stress. Females lay 2–4 ovoid eggs, reach sexual maturity at about 60 mm snout–vent length, and likely produce multiple clutches each year. We remove Salea rosaceum Thominot from the synonymy of Dendragama boulengeri and argue that the unique holotype of S. rosaceum is a specimen of Pseudocalotes tympanistriga with incorrect locality information.