OrderByDescending not working properly in Linq

I am using Linq and have the following code in C#: ``` leaves = GetAnnualLeaves(); otherleaves = GetOtherLeaves(); leaves.AddRange(otherleaves); leaves.OrderByDescending(e => e.StartDate); ``` Basically I am trying to display list of annual and other leaves and I want to display them in DESCENDING order. Problem is it always shows "Other Leaves" at the end of "Annual Leaves" no matter what. So basically it displays like this: ``` 2013-06-29 Annual 2012-01-01 Annual 2011-05-02 Annual 2013-05-01 Other ``` When in fact it should display like this: ``` 2013-06-29 Annual 2013-05-01 Other 2012-01-01 Annual 2011-05-02 Annual ``` Any idea why order by descending is not working? EDIT I am getting casting error when I use CONCAT. Both "Annual" and "Other" leaves are of same type but when I do ``` leaves = leaves.Concat(otherleaves) ``` then the project doesn't compile and gives error ``` Cannot implicitly convert type System.Collections.Generic.IEnumerable<MyEntity> to System.Collections.Generic.List<MyEntity> ``` And if I do type cast: ``` leaves = (List<MyEntity>)leaves.Concat(otherleaves) ``` then I get runtime error.