Recursively cloning React children

gistfile1.js

var RecursiveChildComponent = React.createClass({
  render() {
    return <div>
      {this.recursiveCloneChildren(this.props.children)}
    </div>
  },
  recursiveCloneChildren(children) {
    return React.Children.map(children, child => {
      if(!_.isObject(child)) return child;
      var childProps = {someNew: "propToAdd"};
      childProps.children = this.recursiveCloneChildren(child.props.children);
      return React.cloneElement(child, childProps);
    })
  }
})

What if a child component has no children, but returns a tree, and you want to recursively clone / modify the returned tree?