Thanks, both.  I've currently got the John Wright 'Hedgerow' book on load from the library, and am finding it entertaining reading, but much of the edible stuff he covers is not for me.  I'm looking for something that gives a wider coverage of berries and wild fruits.  Having said that, I may try out 'fat hen' when it is in season again.  I helped to clear a field of the stuff last week (before I read of its spinach-like qualities) - all went on a big bonfire.    However, I think it was well past its best, so perhaps it's just as well I wait for the new stuff.  Had a taste of home-grown hairy bittercress today - reckon it would be real nice on a cheese sandwich.