The package supports drawing proof trees of the kind often used in introductory logic classes, especially those aimed at students without strong mathematical backgrounds. Hodges (1991) is one example of a text which uses this system. When teaching such a system it is especially useful to annotate the tree with line numbers, justifications and explanations of branch closures. prooftrees provides a single environment, prooftree, and a variety of tools for annotating, customising and highlighting such trees. A cross-referencing system is provided for trees which cite line numbers in justifications for proof lines or branch closures. prooftrees is based on forest and, hence, TikZ. The package requires version 2.1+ of forest for expected results. It will not work with versions prior to 2.1.