[flexcoders] How do I remove the arrow for a node in the Tree

[randalma2120]

I created a Tree with new icons for folderOpen and folderClosed but I
still have the arrow. Can someone show or point me to how to remove this.

Used this is the CSS

Tree {
        defaultLeafIcon: Embed("icons/application.png");
        folderOpenIcon: Embed("icons/minus.png");
        folderClosedIcon: Embed("icons/plus.png");
        }

Data is simple:

    <mx:XMLList id="treeData">
            <node label="Students">
                <node label="Report 1" />
                <node label="Report 2"/>
                <node label="Report 3"/>
                <node label="Report 4"/>
                <node label="Listing by Program">
                     <node label="Report 1" />
                        <node label="Report 2"/>
                        <node label="Report 3"/>
                </node>
                </node> 
    </mx:XMLList>