I have some clumps of a very coarse rough grass invading my lawn. Each
clump is about 2" (5cm) to 10" (25cm) in diameter, and is composed of
hundreds of grass 'plantlets'. This is on a heavy clay soil in Essex, UK.
I have controlled it by pulling it up, but it comes back after a season.

A photograph of a grass plantlet can be seen here
http://ucosm.tripod.com/photos/grass6.jpg (21KB). The plantlet
photographed measures approx 4" (10cm) from root to leaftip.

Can anyone identify this grass, and offer any advice about removing it?

TIA
Susan