is an option for Tree and related functions that specifies what style should be used for edge labels.


  • ParentEdgeLabelStyle allows specifying the label style of the parent edge of the root node of a tree, as well as that of any subtrees at positions matching a pattern.
  • Any style specification as used in Style can be used as a setting for ParentEdgeLabelStyle.
  • The following option settings can be used:
  • Automaticuse the atomatic setting for style
    styleuse style for the edge label
    {pos1->style1,pos2->style2,}use stylei for the edge label at relative position posi
    {patt1style1,patt2style2,}use stylei for the edges at positions matching the pattern patti
  • Subtrees with no explicit edge label style are taken to use the automatic style.
  • Color directives such as Red, as well as text specifications such as Bold or Small, can be given.
  • To specify multiple style directives, use Directive[style1,style2,].
  • Giving the option setting ParentEdgeLabelStylestyle is effectively equivalent to replacing the label-like elements of a formatting or related construct by Style[label,style].
  • Edge label specifications are effectively applied in the order ParentEdgeLabel, ParentEdgeLabelStyle and ParentEdgeLabelFunction, with later specifications overriding earlier ones.
  • In ParentEdgeLabelStyle, Allstyle uses style for all subtrees.
  • In ParentEdgeLabelStyle, TreeCases[pattern]style uses style for all subtrees with data matching pattern.


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Basic Examples  (4)

Style an individual edge label:

Style all edge labels:

Use the same style for all edge labels:

Specify positions using position patterns:

Specify positions using data patterns:

Properties & Relations  (4)

Styles for edge labels can be specified by position:

Styles specified by a subtree take precedence over styles specified by its ancestors:

A position {i,j,} in a subtree refers to its subtree at relative position {i,j,}:

A relative position {2} at position {1} refers to the global position {1,2}:

In general, a pattern patt applies to subtrees at global position {i,j,} that match patt:

A list of patterns {patt1,patt2,} applies to relative positions {i,j,} that match the patti:

Wolfram Research (2022), ParentEdgeLabelStyle, Wolfram Language function,


Wolfram Research (2022), ParentEdgeLabelStyle, Wolfram Language function,


Wolfram Language. 2022. "ParentEdgeLabelStyle." Wolfram Language & System Documentation Center. Wolfram Research.


Wolfram Language. (2022). ParentEdgeLabelStyle. Wolfram Language & System Documentation Center. Retrieved from


@misc{reference.wolfram_2024_parentedgelabelstyle, author="Wolfram Research", title="{ParentEdgeLabelStyle}", year="2022", howpublished="\url{}", note=[Accessed: 23-June-2024 ]}


@online{reference.wolfram_2024_parentedgelabelstyle, organization={Wolfram Research}, title={ParentEdgeLabelStyle}, year={2022}, url={}, note=[Accessed: 23-June-2024 ]}