Assembling phylogenetic trees for groups of organisms with thousands of taxa is problematic because of the large amount of data and trees that must be generated and analyzed. Several attempts have been made to develop a better way to handle the problems of large trees. Meta-trees (Meta Supertrees) are suggested as a way to generate a phylogeny for groups where you have many different data sets of overlapping but not identical sets of taxa and without a common set of markers. Meta-trees graft phylogenies onto a fixed base tree and avoid the problems of missing or redundant data and misplaced taxa that plague other types of supertrees. Supertrees are constructed from novel analyses of multiple independently de-rived tree topologies or data matrices with overlapping but not identical taxa. They can provide an excellent summary of past work and a useful framework for exam-ining character evolution in a broader historic and phylogenetic framework. For all types of supertrees, the major concern is how reliable they are at providing an estimate of phylogenetic relationships, or how much confidence can be placed in each of the nodes and the taxonomic associations they indicate. As with all types of analyses, the worth of the product is based on the quality of the data used and the reliability of the method. It seems that the term was first used by Gordon (1986) but then languished until it was made popular by Sanderson et al. (1998) in conjunction with developing taxonomically broad ''trees of life.'' In the last five years, with the advent of large-scale phylogenetic programs, using