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Nature

16
Dec

Flower’s False Pollen Lures Unwitting Bees To Do Its Bidding

Ever heard of a cross-dressing plant? Botanist Chris Martine has discovered one in the middle of the harsh Australian outback. He’s dubbed it Solanum cowiei after botanist Ian Cowie, who first introduced Martine to the plant. Here’s Elizabeth Preston, writing at Inkfish:

It’s a scrappy, spiny shrub with crinkly purple flowers that thrives on fire. It also uses treachery to survive, disguising its female flowers with fake male parts and even fake pollen.

pollen-bee
Many plants rely on bees to transport their pollen from one flower to another. Solanum cowiei does, too, but with a twist.

After assessing the plant’s DNA, Martine concluded that S. cowiei’s ability to reach its pollinators (and thereby survive fires that sometimes ravage the area) is rooted in its edgy sexual behavior:

The new species’s method of reaching those pollinators is a weird one. S. cowiei grows separate male and female flowers, and like about a dozen of its close relatives, it disguises the female flowers with fake male parts and pollen. Under an electron microscope, the false pollen grains look like brand-new tennis balls. Real pollen grains are closer to old ping-pong balls, with large dents or grooves on their surface—these are the weak spots where a narrow tube may later burst out of the wall of the pollen grain, carrying the plant’s sperm to an egg.

The false pollen grains serve as an attraction and a diversion. Since the flower lacks a strong smell, the plant attracts certain foraging bees, which pick up the false grains and feed them to their young. Meanwhile, the true pollen grains hitch a ride on the bees’ bodies, just like pollen from flowers with a flashy scent.

It’s a symbiotic relationship—one of many in the natural world. The carnivorous pitcher plant Nepenthes bicalcarata, for one, uses live-in ants—that feed on the plant’s nectar—to its advantage. Watch our video to find out how: