Cistus and halimiums are the host plants for the parasitic genus Cytinus. These plants take all their nourishment from the roots of their hosts and so have no need of leaves or other conventional green plant parts. They reveal themselves only at flowering time when their tight clusters of small very showy flowers erupt from the ground beneath the host plant.
The two species commonly seen are Cytinus ruber, with bright red and white flowers and Cytinus hypocistis, with flowers of orange and yellow.
Cytinus ruber parasitic on Cistus albidus at Fontfroide, France
Cytinus hypocistis parasitic on Halimium halimifolium in Portugal