Flower Quiz

This is flowering in our garden at the moment. Each flower spike carries about 20 blooms. The interesting thing is that there appears to be two distinct flowers all the way up the spike with different colouring and different stamens. The flowers are hermaphrodite. This means that they have perfect flowers with both sexes represented in one flower. I have read that once a flower has been pollinated by the bee it then turns from having a yellow patch to deep pink. One of the flowers here has not been pollinated, one is just turning pink and the other has turned completely pink.
If anyone gives the correct answer I shall save their comment until after I have given the name of the flower, which will be Monday evening 27th May at 22.00 hours GMT.