A blue flowered lobelia, cascading over the side of a concrete pot.
Each fragile flower holds out three, flat petals, offering an easy landing for passing pollinators.
The nectar is hidden at the bottom of a long tube, below the stamens, so this tiny wasp will get well coated with pollen before it leaves.
Lobelia blue is one of those strange, shifting flower colours that is part pigment and part surface effect. Move your head or your camera and the colour changes.
When I focussed on their delicate shadows the flowers themselves disappeared in a lilac mist.