Index: add_curve_ivygen.py
===================================================================
--- add_curve_ivygen.py	(revision 3110)
+++ add_curve_ivygen.py	(working copy)
@@ -663,7 +663,7 @@
 
 def menu_func(self, context):
     self.layout.operator(IvyGen.bl_idname, text="Add Ivy to Mesh",
-                                                icon='PLUGIN').updateIvy = True
+                                                icon='CURVE_IVY').updateIvy = True
 
 
 def register():
Index: add_curve_sapling/__init__.py
===================================================================
--- add_curve_sapling/__init__.py	(revision 3110)
+++ add_curve_sapling/__init__.py	(working copy)
@@ -560,7 +560,7 @@
 
 
 def menu_func(self, context):
-    self.layout.operator(AddTree.bl_idname, text="Add Tree", icon='PLUGIN')
+    self.layout.operator(AddTree.bl_idname, text="Add Tree", icon='CURVE_SAPLING')
 
 
 def register():
Index: add_mesh_ant_landscape.py
===================================================================
--- add_mesh_ant_landscape.py	(revision 3110)
+++ add_mesh_ant_landscape.py	(working copy)
@@ -804,7 +804,7 @@
 
     # Define "Landscape" menu
 def menu_func_landscape(self, context):
-    self.layout.operator(landscape_add.bl_idname, text="Landscape", icon="PLUGIN")
+    self.layout.operator(landscape_add.bl_idname, text="Landscape", icon="MESH_LANDSCAPE")
 
 def register():
     bpy.utils.register_module(__name__)