The Caption property allows you to specify a string caption to be displayed at the top of the TreeList control. See the figure below.

The caption is displayed in the panel whose visibility is specified by the TreeListOptionsView.ShowCaption property (accessible through the OptionsView property). By default, the caption panel is hidden. Set this property to true to display the caption panel.
By default, the caption panel height is calculated automatically based on the appearance settings (see TreeListAppearanceCollection.Caption property). You can also specify a custom caption panel height using the CaptionHeight property. However, if this property specifies a height insufficient to display the caption in its entirety, the minimum required value is used.