is mildew covered lambs' lettuce edible?
 

I was about to pick my lambs lettuce for dinner, when I noticed a lot
of the leaves are covered in mildew. Even if I try to pick for eating
leaves which look reasonably unaffected I would be bound to end up
eating some, so does anyone know if it's safe to eat? Would washing it
off before eating be okay?

Seems such a shame not to eat it after going to the effort of growing
it, please help!

Clare.