While they're often confused with one another – and both loved by pollinators – pollen and nectar are in fact quite different.
What is nectar?
Nectar is a plant’s way of bribing insects and other animals to pollinate it or protect it against herbivores. The sugar-rich fluid is indeed packed with energy, but it also contains other much-sought-after compounds.
The caffeine contained in citrus tree nectar boosts honeybees’ memories, for instance, making the insects more likely to visit similar flowers. And several nectar components have been found to reduce gut parasite load in bumblebees.
Intriguingly, a chemical component of rhododendron nectar is actually toxic to honeybees but not bumblebees, perhaps because it pays for the plants to encourage only certain, specialist pollinators.
What is pollen?
Sexual reproduction involves the combining of genetic material from two parents (male and female) to produce offspring. In flowering plants, the female’s genetic contribution is contained in a part of a flower called an ovule (which will become a seed once fertilised), and the male’s in a pollen grain (produced by a flower’s anthers).
En masse, pollen appears as a fine, yellow dust. It is usually transported to the female parts of flowers on the wind or by pollinating insects in exchange for nectar.
Nectar vs pollen: what's the difference?
While bees collect both nectar and pollen, they're used for different purposes. When bees visit flowers, they gather pollen and some of this falls off onto other flowers – which helps pollination. Bees will also collect pollen and use it to feed their young. Some beetles and wasps eat pollen.
A flower's nectar will lure bees in to encourage pollination, and provides bees with the energy to fly and pollinate more flowers. Butterflies, other flies and some beetles also drink nectar for energy.
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Main image: a bee pollinates a flower. Credit: Getty