diff --git a/src/renderers/dom/client/ReactMount.js b/src/renderers/dom/client/ReactMount.js
index 4db71492bbdd6..2db80798b269a 100644
--- a/src/renderers/dom/client/ReactMount.js
+++ b/src/renderers/dom/client/ReactMount.js
@@ -83,14 +83,12 @@ function internalGetID(node) {
  * Mounts this component and inserts it into the DOM.
  *
  * @param {ReactComponent} componentInstance The instance to mount.
- * @param {string} rootID DOM ID of the root node.
  * @param {DOMElement} container DOM element to mount into.
  * @param {ReactReconcileTransaction} transaction
  * @param {boolean} shouldReuseMarkup If true, do not insert markup
  */
 function mountComponentIntoNode(
   wrapperInstance,
-  rootID,
   container,
   transaction,
   shouldReuseMarkup,
@@ -98,7 +96,6 @@ function mountComponentIntoNode(
 ) {
   var markup = ReactReconciler.mountComponent(
     wrapperInstance,
-    rootID,
     transaction,
     null,
     ReactDOMContainerInfo(wrapperInstance, container),
@@ -118,13 +115,11 @@ function mountComponentIntoNode(
  * Batched mount.
  *
  * @param {ReactComponent} componentInstance The instance to mount.
- * @param {string} rootID DOM ID of the root node.
  * @param {DOMElement} container DOM element to mount into.
  * @param {boolean} shouldReuseMarkup If true, do not insert markup
  */
 function batchedMountComponentIntoNode(
   componentInstance,
-  rootID,
   container,
   shouldReuseMarkup,
   context
@@ -137,7 +132,6 @@ function batchedMountComponentIntoNode(
     mountComponentIntoNode,
     null,
     componentInstance,
-    rootID,
     container,
     transaction,
     shouldReuseMarkup,
@@ -311,7 +305,6 @@ var ReactMount = {
     ReactUpdates.batchedUpdates(
       batchedMountComponentIntoNode,
       componentInstance,
-      '',
       container,
       shouldReuseMarkup,
       context
diff --git a/src/renderers/dom/server/ReactServerRendering.js b/src/renderers/dom/server/ReactServerRendering.js
index ffec7fcdf5a5a..c80c1dad95849 100644
--- a/src/renderers/dom/server/ReactServerRendering.js
+++ b/src/renderers/dom/server/ReactServerRendering.js
@@ -43,7 +43,6 @@ function renderToStringImpl(element, makeStaticMarkup) {
     return transaction.perform(function() {
       var componentInstance = instantiateReactComponent(element, null);
       var markup = componentInstance.mountComponent(
-        '',
         transaction,
         null,
         ReactDOMContainerInfo(),
diff --git a/src/renderers/dom/shared/ReactDOMComponent.js b/src/renderers/dom/shared/ReactDOMComponent.js
index 27ed5b6767cc4..6b7a8ec659c1b 100644
--- a/src/renderers/dom/shared/ReactDOMComponent.js
+++ b/src/renderers/dom/shared/ReactDOMComponent.js
@@ -543,7 +543,6 @@ ReactDOMComponent.Mixin = {
    * is not idempotent.
    *
    * @internal
-   * @param {string} rootID The root DOM ID for this node.
    * @param {ReactReconcileTransaction|ReactServerRenderingTransaction} transaction
    * @param {?ReactDOMComponent} the containing DOM component instance
    * @param {?object} info about the native container
@@ -551,7 +550,6 @@ ReactDOMComponent.Mixin = {
    * @return {string} The computed markup.
    */
   mountComponent: function(
-    rootID,
     transaction,
     nativeParent,
     nativeContainerInfo,
diff --git a/src/renderers/dom/shared/ReactDOMTextComponent.js b/src/renderers/dom/shared/ReactDOMTextComponent.js
index 4ffa9c4746d0b..d45fa1a4489b0 100644
--- a/src/renderers/dom/shared/ReactDOMTextComponent.js
+++ b/src/renderers/dom/shared/ReactDOMTextComponent.js
@@ -66,13 +66,11 @@ assign(ReactDOMTextComponent.prototype, {
    * Creates the markup for this text node. This node is not intended to have
    * any features besides containing text content.
    *
-   * @param {string} rootID DOM ID of the root node.
    * @param {ReactReconcileTransaction|ReactServerRenderingTransaction} transaction
    * @return {string} Markup for this text node.
    * @internal
    */
   mountComponent: function(
-    rootID,
     transaction,
     nativeParent,
     nativeContainerInfo,
diff --git a/src/renderers/shared/reconciler/ReactCompositeComponent.js b/src/renderers/shared/reconciler/ReactCompositeComponent.js
index 22e5cc2b9a0fb..b341eec2f8d37 100644
--- a/src/renderers/shared/reconciler/ReactCompositeComponent.js
+++ b/src/renderers/shared/reconciler/ReactCompositeComponent.js
@@ -120,7 +120,6 @@ var ReactCompositeComponentMixin = {
   /**
    * Initializes the component, renders markup, and registers event listeners.
    *
-   * @param {string} rootID DOM ID of the root node.
    * @param {ReactReconcileTransaction|ReactServerRenderingTransaction} transaction
    * @param {?object} nativeParent
    * @param {?object} nativeContainerInfo
@@ -130,7 +129,6 @@ var ReactCompositeComponentMixin = {
    * @internal
    */
   mountComponent: function(
-    rootID,
     transaction,
     nativeParent,
     nativeContainerInfo,
@@ -138,7 +136,6 @@ var ReactCompositeComponentMixin = {
   ) {
     this._context = context;
     this._mountOrder = nextMountID++;
-    this._rootNodeID = rootID;
     this._nativeParent = nativeParent;
     this._nativeContainerInfo = nativeContainerInfo;
 
@@ -302,7 +299,6 @@ var ReactCompositeComponentMixin = {
 
     var markup = ReactReconciler.mountComponent(
       this._renderedComponent,
-      rootID,
       transaction,
       nativeParent,
       nativeContainerInfo,
@@ -764,7 +760,6 @@ var ReactCompositeComponentMixin = {
       );
       var nextMarkup = ReactReconciler.mountComponent(
         this._renderedComponent,
-        this._rootNodeID,
         transaction,
         this._nativeParent,
         this._nativeContainerInfo,
diff --git a/src/renderers/shared/reconciler/ReactEmptyComponent.js b/src/renderers/shared/reconciler/ReactEmptyComponent.js
index c9df64d031680..3095638b4ec70 100644
--- a/src/renderers/shared/reconciler/ReactEmptyComponent.js
+++ b/src/renderers/shared/reconciler/ReactEmptyComponent.js
@@ -26,23 +26,19 @@ var ReactEmptyComponentInjection = {
 
 var ReactEmptyComponent = function(instantiate) {
   this._currentElement = null;
-  this._rootNodeID = null;
   this._renderedComponent = instantiate(placeholderElement);
 };
 assign(ReactEmptyComponent.prototype, {
   construct: function(element) {
   },
   mountComponent: function(
-    rootID,
     transaction,
     nativeParent,
     nativeContainerInfo,
     context
   ) {
-    this._rootNodeID = rootID;
     return ReactReconciler.mountComponent(
       this._renderedComponent,
-      rootID,
       transaction,
       nativeParent,
       nativeContainerInfo,
@@ -54,9 +50,8 @@ assign(ReactEmptyComponent.prototype, {
   getNativeNode: function() {
     return ReactReconciler.getNativeNode(this._renderedComponent);
   },
-  unmountComponent: function(rootID, transaction, context) {
+  unmountComponent: function() {
     ReactReconciler.unmountComponent(this._renderedComponent);
-    this._rootNodeID = null;
     this._renderedComponent = null;
   },
 });
diff --git a/src/renderers/shared/reconciler/ReactMultiChild.js b/src/renderers/shared/reconciler/ReactMultiChild.js
index 1b0be8c5631f4..39c5a7a2fde7c 100644
--- a/src/renderers/shared/reconciler/ReactMultiChild.js
+++ b/src/renderers/shared/reconciler/ReactMultiChild.js
@@ -251,7 +251,6 @@ var ReactMultiChild = {
           var child = children[name];
           var mountImage = ReactReconciler.mountComponent(
             child,
-            name,
             transaction,
             this,
             this._nativeContainerInfo,
@@ -394,8 +393,8 @@ var ReactMultiChild = {
             this._unmountChild(prevChild);
           }
           // The child must be instantiated before it's mounted.
-          this._mountChildByNameAtIndex(
-            nextChild, name, nextIndex, transaction, context
+          this._mountChildAtIndex(
+            nextChild, nextIndex, transaction, context
           );
         }
         nextIndex++;
@@ -502,15 +501,13 @@ var ReactMultiChild = {
      * @param {ReactReconcileTransaction} transaction
      * @private
      */
-    _mountChildByNameAtIndex: function(
+    _mountChildAtIndex: function(
       child,
-      name,
       index,
       transaction,
       context) {
       var mountImage = ReactReconciler.mountComponent(
         child,
-        name,
         transaction,
         this,
         this._nativeContainerInfo,
diff --git a/src/renderers/shared/reconciler/ReactReconciler.js b/src/renderers/shared/reconciler/ReactReconciler.js
index 7b3f453e1aab7..795933f2d73a6 100644
--- a/src/renderers/shared/reconciler/ReactReconciler.js
+++ b/src/renderers/shared/reconciler/ReactReconciler.js
@@ -27,7 +27,6 @@ var ReactReconciler = {
    * Initializes the component, renders markup, and registers event listeners.
    *
    * @param {ReactComponent} internalInstance
-   * @param {string} rootID DOM ID of the root node.
    * @param {ReactReconcileTransaction|ReactServerRenderingTransaction} transaction
    * @param {?object} the containing native component instance
    * @param {?object} info about the native container
@@ -37,14 +36,12 @@ var ReactReconciler = {
    */
   mountComponent: function(
     internalInstance,
-    rootID,
     transaction,
     nativeParent,
     nativeContainerInfo,
     context
   ) {
     var markup = internalInstance.mountComponent(
-      rootID,
       transaction,
       nativeParent,
       nativeContainerInfo,
diff --git a/src/test/ReactTestUtils.js b/src/test/ReactTestUtils.js
index 464502638a962..b7c4cd5d931ba 100644
--- a/src/test/ReactTestUtils.js
+++ b/src/test/ReactTestUtils.js
@@ -11,7 +11,6 @@
 
 'use strict';
 
-var ClientReactRootIndex = require('ClientReactRootIndex');
 var EventConstants = require('EventConstants');
 var EventPluginHub = require('EventPluginHub');
 var EventPluginRegistry = require('EventPluginRegistry');
@@ -22,7 +21,6 @@ var ReactDOMComponentTree = require('ReactDOMComponentTree');
 var ReactElement = require('ReactElement');
 var ReactBrowserEventEmitter = require('ReactBrowserEventEmitter');
 var ReactCompositeComponent = require('ReactCompositeComponent');
-var ReactInstanceHandles = require('ReactInstanceHandles');
 var ReactInstanceMap = require('ReactInstanceMap');
 var ReactUpdates = require('ReactUpdates');
 var SyntheticEvent = require('SyntheticEvent');
@@ -447,13 +445,10 @@ ReactShallowRenderer.prototype._render = function(element, transaction, context)
   if (this._instance) {
     this._instance.receiveComponent(element, transaction, context);
   } else {
-    var rootID = ReactInstanceHandles.createReactRootID(
-      ClientReactRootIndex.createReactRootIndex()
-    );
     var instance = new ShallowComponentWrapper(element.type);
     instance.construct(element);
 
-    instance.mountComponent(rootID, transaction, null, null, context);
+    instance.mountComponent(transaction, null, null, context);
 
     this._instance = instance;
   }