I'm not sure if this is something to be worried about or not, but I've got a few pots of parsley growing and most of it has these strange white dots at the tip of each leaf - see image below (you'll need to view full image to see them). The uniformity of them would rule out a bug, is it an infection or is it just something that happens with parsley? Don't want to eat it in case there's something wrong with it.