Nikolai Mavrenkov already created a good description of the problem on Stack Overflow: http://stackoverflow.com/questions/36893449/textarea-placeholder-isnt-shown-in-ie-11-being-rendered-using-react

I just can confirm it breaks in IE11, but works in IE10 (and other browsers) with React v15.0.2.

if (newValue !== node.value) {
        node.value = newValue;
      }
      if (props.defaultValue == null) {
        node.defaultValue = newValue;
      }
    }
    if (props.defaultValue != null) {
      node.defaultValue = props.defaultValue;
    }
  },
  postMountWrapper: function(inst) {
    
    
    var node = ReactDOMComponentTree.getNodeFromInstance(inst);
    
    node.value = node.textContent; 
  },
};
function _handleChange(event) {
  var props = this._currentElement.props;
  var returnValue;
  if (props.onChange) {
    returnValue = props.onChange.call(undefined, event);
  }
  ReactUpdates.asap(forceUpdateIfMounted, this);
  return returnValue;
}
module.exports = ReactDOMTextarea;