I've never heard of any books which cover root depth on every single available plant. Maybe you can rephrase the question and give some ideas on what you would like to plant and you may get some answers that way....
Is there some particular reason why depth is important for you? If you have a concern please share and I'm sure you will get some help :)

Vera

not knowing what the application is, i thought the shallow root depth might be similar to a green roof planting.

i know there are several species of sedums that usually preferred for green roof design...chives is another one.

you may want to do a web search for "green roof plantings" and you could come up with a list of plants that might be what you are looking for...