A perfect memory: rockrose.
I wondered how the sticky leaves served the plant. It isn’t carnivorous; I didn’t see any little insects stuck on the leaves. As far as I can tell it is a Cistus libanotis ?shrub. They were abundant next to the roads, growing in the dry, sandy soil. I did see them, or another variety with slightly smaller flowers, also white, as we drove up to Fóia, the highest mountain of Algarve. There was a bird nest on every pole or chimney!