I didn't know what either of these two wildflowers were. I was attracted to them for very different reasons. The first just struck me as being rather artistic and interesting, its spiky red right-angled stems and bright yellow flowers contrasting with the backdrop of dark water dotted with flecks of spume. It has taken me a long time to identify it but I believe it's called wall lettuce (see HERE). It was growing in a crack in the concrete of the aqueduct, not quite a wall but almost.
The one below really stood out, the colour a piercing blue. I thought at first it was some kind of forget-me-not and, indeed, it is loosely related but I have now identified it, fairly confidently, as green alkanet. (See HERE). Apparently it's a pernicious weed that you don't really want in the garden, though here by the side of a lane against an old stone wall, it brought cheer to a dark spot.
I love learning new things.