Nectar guide

nectar, pollen, or both, but various plants produce oil,^[1] resins,^[2] scents,^[3] or waxes. Such patterns also are known as "pollen guides" and "honey guides", though some authorities argue for the abandonment of such terms in favour of floral guides (see for example Dinkel & Lunau^[4]). Pollinator visitation can select for various floral traits, including nectar guides through a process called pollinator-mediated selection

sunflowers, they are visible only when viewed in ultraviolet light. Under ultraviolet, the flowers have a darker center, where the nectaries are located, and often specific patterns upon the petals as well. This is believed to make the flowers more attractive to pollinators such as honey bees and other insects that can see ultraviolet. This page on butterflies shows an animated comparison of black-eyed Susan (Rudbeckia hirta) flowers in visible and UV light.^{[citation needed}