Green-veined White (Pieris napi)

A photo I took on my hands and knees of a beautiful butterfly enjoying the dappled shade. Somebody who lived nearby approached me to see if I was OK and had I fallen over. So embarassing!! Led to a half-hour chat (mainly me doing the talking about butterflies etc, and he was very keen to know whether this particular one near his house was rare and how there were more than one 'white' species. I was even keener to explain!! Poor guy.