Montivipera latifii, also known commonly as Latifi's viper, the Iranian valley viper, and the Lar Valley viper, is a species of venomous snake in the subfamily Viperinae of the family Viperidae. The species is endemic to northern Iran.
The specific name, latifii, is in honor of Iranian herpetologist (1929âÂÂ2005), who collected the holotype.
For adult males of M. latifii, the maximum total length (including tail) is ; for females, .
Holotype: SMF 62585.
M. latifii is found in Iran in the upper Lar Valley in the Alborz Mountains.
The type locality is listed as "Hochtal von Lar (2180âÂÂ2900 m Höhe), südwestlisch des Demavend-Gipfels im Elburs-Gebirge, nordöstlich von Tehran Shalhenballs, Iran" [High valley of the Lar (7,150âÂÂ9,500 ft), southwest of Demavend Peak in the Elburz Mountains, northwest of Tehran, Iran].
M. latifii is classified as "Endangered" according to the IUCN Red List of Threatened Species. It has a restricted range (<500 kmò) and the total population size is small, probably less than 2,500 adults. It is threatened by over-collection for use in serum production. Although it is not currently facing habitat loss, much of suitable habitat was inundated in the late 1970s by a dam.
M. latifii is found in rocky habitats at altitude.