Cunning plants use a bag of tricks to lure pollinators

Giant swallowtail butterfly nectaring on the easily accessible flowers of Crassula falcata, or helicopter plant. (Sharon Reeve)

PUBLISHED: June 14, 2025 at 5:30 AM PDT

By Sharon Reeves

For The Union-Tribune

Plants are anchored in one spot, but they are cunning. They have mastered the art of enticing more mobile organisms to do their bidding. It is the goal of every living thing to procreate and to live on through their offspring. Plants are no exception.

There are many pollination strategies employed by plants. Wind pollination is highly inefficient and self-pollination does not allow for evolution, so many plant species have evolved to entice and use insects and animals to pollinate themselves. One of the strategies used by plants to lure pollinators is to supply sweet nectar and nutritious high-protein pollen in the hopes that some of the pollen is not eaten but taken to other plants for pollination.

Everyone loves sweets, and it seems that insects, animals and birds are no exception. Plants make sweet nectar to bring in visitors to their flowers. The ultimate goal, of course, is to transfer male pollen to the female stigma of another plant of the same species. Some orchids even go so far as to create structures that look like female bees to attract male bees. Male bees are fooled by these lookalikes and will attempt to copulate with them and, in doing so, will spread the pollen of the orchid. This trickery is a cost-saving measure in that the orchid does not have to manufacture nectar or prodigious amounts of expensive pollen.

Common buckeye butterfly, resting on a native penstemon, and absorbing solar radiation through its dark-colored wings. (Sharon Reeve) — A common buckeye butterfly rests on a native penstemon and absorbs solar radiation through its dark-colored wings. (Sharon Reeve)

While bees are the main pollinator of plants, there are other organisms that augment pollination, namely butterflies, hummingbirds, flies, wasps, bats and beetles. Here, I talk about butterflies, flies and bats.

Butterflies are the flashy of the genus Lepidoptera. Many of them have evolved to use highly toxic plants as caterpillar host plants to keep from being eaten. Bright colors also sexual fitness, serve as camouflage or mimic other more toxic butterflies. In the animal kingdom, orange is the color of danger and frequently employed by butterflies. Dark wing colors act as solar collectors to warm the butterfly on cold days.

Butterflies can see in the ultraviolet light spectrum; the pigmented scales that make up the wing can also look very different under UV light. Plants frequently have markings only visible in the UV spectrum that the location of nectar and pollen. Butterflies use their long, coiled proboscis like a straw to sip nectar. Plants with wide flat flowers like California native buckwheats (Eriogonum sp.) are choice nectar plants for many butterflies.

Stapelia gigantea emits a rotting meat smell to attract its fly pollinators. (Sharon Reeve)

Not only do plants produce nectar for pollinators, but they can also create scents that are irresistible for their pollinator of choice. For example, flies feed on carrion, and plants in the genus Stapelia bloom accompanied by the stench of rotten meat. Is there really rotten meat? No, but the plant has refined the scent of its flowers to attract large quantities of flies to pollinate.

I have many species of Stapelia in my garden, and when they bloom they attract a steady influx of flies. Clever plants! This strategy to attract flies is not limited to only the genus Stapelia as other in the family, Araceae, also do this. In fact, the aptly named “skunk cabbage” has the ability to raise the temperature of its flowers to make them smellier while it is blooming.

We think of pollination occurring during the day, but there are a number of organisms that pollinate only at night. Bats and moths take over when the sun goes down. In the dark of night, color and scent become important, which is why bat-pollinated plants bloom primarily white and are very sweetly scented. Bats are efficient pollinators as they are able to transport large amounts of pollen on their furry bodies. Plants have evolved to hang away from the plant to give easier access to incoming bats.

Incredibly large bloom spikes of Agave desmettiana offering a great meal for bats. (Sharon Reeve)

In plants like Agave, pollen and nectar structures are prominently displayed along the huge flowering structure the plant makes before it dies. Agaves only bloom once, and when they do, they grow a bloom spike that is several times larger than the plant, sometimes as high as 15 feet. This is a massive investment of energy and the final chapter in this plant’s life. Agave tequilana (source of tequila) pollen is especially nutritious and 50 percent protein, while the nectar keeps bats flying with 22 percent sugar.

While plants look demure and defenseless, they are actually mighty and clever, with marvelous and wondrous ways to assure pollination.

Reeve is a UCCE Master Gardener since 1998, transferring to California in 2012. She worked for many years as a consulting horticulturist for Monrovia Nurseries, and as a landscape designer for BrightView Landscapes in San Diego. She has a bachelor of science in horticulture, a bachelor of arts in landscape architecture and a master of science in ecology. Reeve writes a gardening column and two blogs about plants. Her thesis work on biological soil crust restoration was published in January 2023.