The Lambda coalescent introduced by Pitman (1999) and Sagitov (1999) is a random tree which has multiple mergers. It is a dual to a Lambda-Fleming-Viot process which describes a population of individuals with births and deaths, where a single individual’s children can contribute a large proportion of the population. The population process has jumps at times where individuals give birth. The Wright-Fisher diffusion in contrast, being a diffusion, is continuous over time. The Kingman coalescent, a random binary tree, is dual to the Wright-Fisher diffusion. This talk will describe Lambda coalescent trees, how they relate to a population of individuals, and a connection with the Wright-Fisher diffusion.