Worth a second look

Gardens should be approached on our knees. So we don't miss things like this:

Flower unfolding from its bud

Comes in blue and lilac, with pin-stripes

I've forgotten what plant this was; it got transplanted by mistake with a batch of primulas. Once the flowers are completely open, I may remember.

UPDATE: It's a Himalayan Blue Poppy, Meconopsis baileyi.