Query XML files with LINQ

If you regularly work with XML, knowing a technique to directly query it can be a real asset.  I have found LINQ to XML together with LINQPad to be really helpful.  The best thing to do is to simply show an example.  Here we have a trivial XML file that we load in and display:

Then, let's say we want to list all plants from the file:

The tricky part is that if there are namespaces in your xml (and there usually is), then you need to include the namepace in braces.