If you key in "wild purslane" into the database, for the wild purslane, I "think" you will choose the first one:
Purslane Oleracea
and the reason I think that is the others are "named" like what you would buy at a nursery.
I don't know who the moderator is for purslane in the db, but if it's wrong, they will let you know, if not you'll get an acorn
