The Webster's salamander (Plethodon websteri) is a species of salamander in the family Plethodontidae. It is endemic to the southeast United States, in patchy and disjunct lowland subpopulations ranging from South Carolina to Louisiana. Its natural habitat is mixed mesophytic temperate forests, in association with rocky streams and outcrops. Description Webster's salamander is a cryptic species which is morphologically nearly indistinguishable from several other eastern Plethodon species, including red-backed salamanders (P. cinereus, P. serratus) and zigzag salamanders (P. angusticlavius, P. dorsalis, P. ventralis). Like these species, Webster's salamander is a small plethodontid with a wide range of color patterns on a dark brown background. The back often has a red, orange, or yellow dorsal stripe which may have irregular edges, or it may be unstriped entirely. The dorsal stripe, when present, is typically brighter on the tail than the torso. The flanks and underside are speckled with white, red, and black. Webster's salamander is mainly differentiated through genetic data and its geographic range, which mostly does not overlap with similar species. There is some sympatric overlap with the southern zigzag salamander (P. ventralis) in northern Alabama. Although these species may be confused with each other in that area, they never hybridize, and P. websteri is usually found in a striped morph while P. ventralis is usually in an unstriped morph where they co-occur. Taxonomy P. websteri was genetically differentiated from P. ventralis (at the time considered a southern population of the northern zigzag salamander, P. dorsalis) in 1979. It was one of the earliest cryptic species to be differentiated primarily on the basis of molecular data. At the time, it was considered to be part of the welleri group, a clade containing zigzag salamanders and Weller's salamander (P. welleri). Later data suggests that it is not closely related to other salamanders in the welleri group, despite its similar appearance. Some studies have even argued that it is closer to slimy salamanders (the glutinosus group), though this is not universally agreed upon. Distinct subpopulations of P. websteri are genetically divergent, and the species is estimated to have split into two major clades approximately 5.3 million years ago. One clade (the "type locality clade") is distributed over most of Alabama and eastern Mississippi. The other clade (the "Semlitch clade") encompasses three subpopulations: one in western Mississippi and Louisiana, another in east-central Alabama, and a third in Georgia and South Carolina. These four