Dear all, I'd like to introduce a new R package called *phylogram,* for working with evolutionary trees as deeply-nested lists known as "dendrogram" objects. The package provides functions for importing and exporting phylogenetic trees in the Newick parenthetic text format, as well as several functions for command-line tree manipulation. With an emphasis on speed and computational efficiency, the *phylogram* package also includes tools for rapidly computing distance matrices, and building large trees using fast alignment-free k-mer counting and divisive clustering. While not guaranteed to produce sufficiently accurate phylogenetic trees for taxonomic purposes, this offers an efficient means of clustering large trees for a variety of other applications including tree-based sequence weighting, guide trees for progressive multiple sequence alignment, and other recursive operations such as classification tree learning. Any feedback is warmly welcomed. vignette: https://cran.r-project.org/web/packages/phylogram/vignettes/phylogram-vignette.html development version: https://github.com/shaunpwilkinson/phylogram bug reports: https://github.com/shaunpwilkinson/phylogram/issues google group: https://groups.google.com/group/phylogram Best regards, Shaun Wilkinson Email: shaunpwilkinson at gmail.com Twitter: @wilkinshau [[alternative HTML version deleted]]