Life

Flowers rely on advertising
Some unusual graffiti has demonstrated just how important advertising signs are among flowers in the wild. Six white streaks on the dark flower of a kind of South African wild iris point to the vital “insert proboscis here” opening for sipping nectar. Scribbling ink over some or all of those guide marks did not make much difference in whether pollinators approached a flower. But few pollinators sipped from defaced flowers, and pollen spread dropped as low as zero, report Dennis Hansen and colleagues at the University of KwaZulu-Natal in South Africa in an upcoming Proceedings of the Royal Society B. —Susan Milius