Luzula species - Wood-rushes
Luzula - Wood-rushes all have hairy margins to their leaves.
Luzula campestris - Field Wood-rush
Luzula pilosa - Hairy Wood-rush
Luzula sylvatica - Great Wood-rush
Luzula multiflora - Heath Wood-rush
There are two subspecies - congesta and multiflora.
These are the main species found in Lanarkshire. Luzula luzuloides -White Wood-rush, has been recorded in Calderglen and Bothwell Castle but not recently.
There is a guide to this family and a detailed key from the BSBI here.