Scientific classification
Binomial name
Lachesis muta

The bushmaster (Lachesis muta) is a venomous snake of the viper family. The bushmaster inhabits forested areas and adjacent clearings of South America. Adults range in length from two to 2½ metres (seven to eight feet) and some individuals may reach three metres (10 ft). The largest known adult was just under 3.65m (12'), making the bushmaster the longest venomous snake in the Western Hemisphere.

The bushmaster is the only neo-tropical pit viper that lays eggs, about a dozen in the average clutch. The female is reported to remain with the eggs during incubation and may aggressively defend the nest if approached. The hatchings average 30 cm (20 in.) in length and are more colorful than the adults.

Subspecies of the bushmaster include:

  • Lachesis muta muta - the nominate race that inhabits Ecuador, Peru and northern Brazil.
  • Lachesis muta stenophyrs - darker colored, lives in Panama and Costa Rica.
  • Lachesis muta rhombeata - eastern Brazil.
  • Lachesis muta melanocephala - southwestern Costa Rica

The bushmaster's bite can be fatal for humans.


  • Living Snakes of the World in Color by John M. Mehrtens, 1987. ISBN 0-8069-6460X

Bushmaster is also the name of an
American firearms manufacturer.