This link might be easier I think it will just take you to the album
http://s987.photobucket.com/albums/ae359/ftmustang1965/Weeds/

Orchardgrass is a clumping type of grass that I don't find to be much of a problem in my yard because it can be mowed and is difficult to distinguish from the others that grow there.

Here is a link that might be useful: About Orchardgrass

by clumping you mean something like this?

That looks a lot like the grass I have in my horse pasture, but it is hard to tell. We have it cut and baled and it is considered "orchard grass hay".

Some of the grass there does exhibit clumping. If you dig those clumps you most likely will find a root mass right under the clump while that other grass there will have roots spread all over.