Watercress

I'm talking "mustard and cress".

 

Try
http://www.marshalls-seeds.co.uk/rkmain.asp?PAGEID=20670&STK_PROD_CODE=1020-2503
Type cress into search bar and you get 4 types. Think I might get some, now that this has reminded me. If I had the room i would have a water cress bed. As we dont have any cattle or sheep then I don't see there is any chance of it getting liver fluke. No more than the mint would have of getting it and that grows in a damp part of the garden. Liver fluke is not unique to water cress, it is just that it lives in the same natural environment. For the same reason don't go nibbling on bits of water mint you find in mountain streams. Also it is not adviseable to drink from mountain streams. They are in the most sheep infested areasd possible.
In some countries the main cause of liver fluke infestation is from eating raw or undercooked fish - but that is from a different specie of fluke.