Flowers Don’t Wave to Gardeners

Flowers don’t wave to gardeners. They grow, they bloom, they wave gently in the breeze, but they don’t wave to gardeners, even if gardeners wave first. They reserve their flirtatious side for pollinators. They only wave to catch the roving eye of insects.

Seriously, this is science news. The botanical headline “Flowers ‘Wave’ at Passing Insects” leapt off the page and led me eventually to the BBC which even devoted a video clip to the topic! (A video clip of a stationary plant, but still, video!) I excerpt that article below:

“I was lying on the beach watching flowers wave in the wind at my daughter’s birthday party, and I wondered why they have stalks and risked getting damaged in such an exposed habitat,” recounted John Warren from the University of Aberystwyth.

So he looked at what research had previously been done, and found very few answers…

Their experiments reveal that flowers mounted on long, thin stalks move around more in the wind…

(Stay with it, this self-evident start does lead to new conclusions.)

This acts as a powerful signal to passing pollinators, allowing the plant to attract more insects than less mobile flowers growing atop short, thick stems.

“We found wavy flowers are more visible to insects, and thus attract more pollinators and set more seeds,” said John Warren.

But flowers ultimately face an evolutionary trade-off, he believes.

“Short, fat-stalked flowers don’t wobble enough and are less attractive to pollinators; yet very wobbly flowers are just too wobbly for the insects to handle, as the insects cannot land on them.

“Only flowers that wobble the right amount are successful in setting seeds.”

Who knew? Well, if anyone did, it wasn’t in the scientific literature before. The new article is “Do flowers wave to attract pollinators? A case study with Silene maritima” by J. Warren & P. James in the Journal of Evolutionary Biology. (The picture at the top of the post is not Silene maritima; it is an Agapanthus photo that I had on hand.)

Many gardeners understand how important pollination is to flower species: that is after all, where seeds come from. Human-bred plants (with, say, extra petals or new colors) may be pretty, but they can be unsuited to the singles bar of natural pollination. A better flower for pollinators leads to more seeds for the flower. And we know flowers use colors, shapes, nectar and scents to ply their botanical wiles. When did “wobbliness” get added to the list of seductive wiles? Just now. All that calming waving-in-the-breeze you’ve seen? Reclassify that as “Dating Game” meets “Desperate Housewives” for flowering plants.

The next time you’re on York Street, stop by the Birds and Bees Walk at Denver Botanic Gardens to learn more about other seductive wiles of the plant kingdom. See the Birds and Bees Walk link here for a picture and short description.