tikz-qtree: edge overlaps with nodes

Question

I'm drawing a tree using the tikz-qtree package. There is a lot of text in the nodes. I'm finding it difficult to get the edges to meet the edge of the nodes. For some nodes with lots of text, the edge goes too far. Code is

\documentclass{minimal}
\usepackage{graphicx}
\usepackage{a4wide}

\usepackage{fullpage}
\usepackage{tikz}

\usetikzlibrary{shapes, positioning, shadows, trees}

\usepackage{tikz-dependency}
\usepackage{tikz-qtree}

\begin{document}
%===================================================

\centering
\begin{tikzpicture}

\tikzset{font=\small,
edge from parent fork down,
level distance=2.7cm,
every node/.style=
{top color=white,
bottom color=blue!10,
rectangle,rounded corners,
%minimum height=8mm,
draw=black,
thick,
align=center,
sibling distance = 4ex,   
%text depth = 0pt
},
edge from parent/.style=
{draw=black,
thick
}}

\Tree [.Morphemes [.Free-standing [.Open-class {cat, chase, dog} ] [.Closed-class {(1) Pronouns; she, him\\(2) Determiners; the, this\\(3) Prepositions; on, at\\(4) Auxilary verbs;\\ \textit{have} done, \textit{is} doing} ] ]
              [.Bound [.Open-class NONE ] [.Closed-class 
              [.Derivational {care-less\\un-wind} ] [.Inflectional {(1) Tense/Agreement marking on verbs;\\He go-es, They laugh-ed\\(2) Plural marking on nouns;\\dog-s, cat-s} ]                 
              ]]
]

\end{tikzpicture}



%====================================================

\end{document}

This is what the overlap looks likes (below). Any hints warmly welcomed.

Answer 1

You need to characterize the path from the parent node to the child node. I take as reference the last example of page 4 in the documentation of tikz-qtree.

Code:

\documentclass{article}
\usepackage{tikz-qtree}
\usetikzlibrary{trees}

\begin{document}
%===================================================

\centering
\begin{tikzpicture}
\tikzset{font=\small,
edge from parent fork down,
level distance=2.7cm,
every node/.style=
{top color=white,
bottom color=blue!10,
rectangle,rounded corners,
%minimum height=8mm,
draw=black,
thick,
align=center,
sibling distance = 4ex,   
%text depth = 0pt
},
edge from parent/.style=
{draw=black,
thick,
% |-|-| here starts the new part
edge from parent path={(\tikzparentnode.south)
-- +(0,-8pt)
-| (\tikzchildnode)}
}}

\Tree [.Morphemes [.Free-standing [.Open-class {cat, chase, dog} ] [.Closed-class {(1) Pronouns; she, him\\(2) Determiners; the, this\\(3) Prepositions; on, at\\(4) Auxilary verbs;\\ \textit{have} done, \textit{is} doing} ] ]
              [.Bound [.Open-class NONE ] [.Closed-class 
              [.Derivational {care-less\\un-wind} ] [.Inflectional {(1) Tense/Agreement marking on verbs;\\He go-es, They laugh-ed\\(2) Plural marking on nouns;\\dog-s, cat-s} ]                 
              ]]
]

\end{tikzpicture}
%====================================================

\end{document}

Result: