The Pseudoflowers
These flowers mimic those of yellow, early spring wildflowers (e.g. buttercups), not only in visible light but also in ultraviolet. Since bees "see" in the ultraviolet range, these flowers are more attractive to the pollinating insects. In addition, the fungus produces a distinct scent to attract insects; this olfactory appeal has allowed the fungus to evolve and "improve" upon the mimicry system by facilitating proper transfer of fungal spermatia. The bees feed on a sweet, sticky substance that the fungus forces the plant to produce on the imitation flowers.
Read more about this topic: Puccinia Monoica