Mystery revisited: Is nocturnal colored nectar a nonadaptive floral trait?

Keywords: colored nectar; deceptive pollination; earwig; pigment; secondary metabolites; stemona EN colored nectar deceptive pollination earwig pigment secondary metabolites stemona 1 6 6 05/05/22 20220501 NES 220501 Colored nectar is an uncommon floral nectar trait that has been known since 1785 in angiosperms, being recorded in 68 taxa from 20 genera in 15 families (Hansen et al., 2007). During studies of the pollination ecology of I S. tuberosa i in the field, we discovered that the flowers of I S. tuberosa i could secrete red colored nectar at ~8:00 PM after the flower beginning to close after sunset (Figure 1b). The colorless nectar of the white flower mutant together with the absence of nectar in experimental removals of stamens showed that the pigment of colored nectar of I S. tuberosa i appeared to stem from red-purple stamens. [Extracted from the article]