diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -325,10 +325,10 @@ void GenerateTrees()
 
 /**
  * Plant a tree.
- * @param tile start tile of area-drag of tree plantation
+ * @param tile end tile of area-drag
  * @param flags type of operation
  * @param p1 tree type, TREE_INVALID means random.
- * @param p2 end tile of area-drag
+ * @param p2 start tile of area-drag of tree plantation
  * @param text unused
  * @return the cost of this operation or an error
  */