%\title{Using the forest package to create trees in LaTeX}
% From http://tex.stackexchange.com/a/108728/23931
\documentclass[10pt,twoside,a4paper]{memoir}
\usepackage{graphicx}
\usepackage{forest}
\usepackage{tikz-qtree}
\begin{document}
\begin{tikzpicture}
\tikzset{edge from parent/.style={draw,edge from parent path={(\tikzparentnode.south)-- +(0,-8pt)-| (\tikzchildnode)}}}
\Tree [.ZZ
[.Bax
[.X
[.Y [.A ] [.B ] ]
[.Z [.C ] [.D ] ] ]
[.F
[.M [.E ] [.F ] ]
[.G [.G ] [.H ] ] ] ]
[.A
[.B
[.S [.I P R T V U ] [.J ] ]
[.I [.K ] [.L ] ] ]
[.M
[.L [.M ] [.N ] ]
[.A [.O ] [.P ] ] ] ] ] ]
\end{tikzpicture}
\begin{forest} for tree={
edge path={\noexpand\path[\forestoption{edge}] (\forestOve{\forestove{@parent}}{name}.parent anchor) -- +(0,-12pt)-| (\forestove{name}.child anchor)\forestoption{edge label};}
}
[ZZ
[Bax
[X
[Y [A ] [B ] ]
[Z [C ] [D ] ] ]
[F
[M [E ] [F ] ]
[G [G ] [H ] ] ] ]
[A
[B
[S [I [P][R][T][V][U]] [J ] ]
[I [K ] [L ] ] ]
[M
[L [M ] [.N ] ]
[A [O ] [P ] ] ] ] ] ]
\end{forest}
\end{document}