Singin' in the Rain

Hello, friends! It’s great to be with you again. Enjoying the long holiday weekend?

After a breather, The Bees’ Knees is easing back into business with a few photos that I hope will put smiles on your faces.

I was recently in New England, which was wilting its way through a drought. Everything was parched. A Smokey Bear sign on the side of the road warned us in bold red letters that the risk of wildfires was "extreme." The night before I visited the Coastal Maine Botanical Gardens, though, a gentle, steady and very welcome rain had fallen. The morning was misty and still. As I strolled the grounds, what ended up catching my eye was not so much the charm of the individual plants or the splendor of the landscape design – captivating though they are – but rather the intricate ways raindrops were clinging to foliage and flowers..

I believe this is a species of Alchemilla, or lady’s mantle. It’s native to the Caucasus and Eastern Carpathians – unfortunately not to North America. Its downy, saucer-shaped leaves are particularly suited to capturing water, though.

Look how the water is clinging even to these smooth, waxy leaves, which belong, I think, to a quaking aspen (Populus tremuloides).

I started wondering why this phenomenon of sustained water-beading on leaves happens. Is it just a physical side effect of rain landing on surfaces that are not perfectly flat and vertical? Or does prolonged contact between the rain and leaves serve some environmental purpose?

As you’ll remember from Bio, plants get most of their water through their roots. They do have stomata, or pores, on their leaves. But these are for releasing water (transpiration) and absorbing carbon dioxide (photosynthesis). In other words, the leaves themselves aren’t “drinking” the water. So why hang onto it?

Foliage of (I think) wild blue indigo (Baptisia australis).

What the spruce tree isn’t capturing, the spider certainly is! Does she drink it? Does it help her lure prey?

Indoor gardeners are sometimes advised to mist the leaves of their plants to increase humidity, which in turn slows transpiration. Do outdoor plants try to manage their own microclimates by holding onto airborne moisture?

It looks as though this joe-pye weed (a species of Eutrochium) has been dusted with glitter.

And behold the sequins on this tall tickseed (Coreopsis tripteris)!

Trees are considered vital to stormwater management because their canopies are great at intercepting rainfall, delaying its journey to the ground, while their roots soak up much of the remainder. Are herbaceous plants (and spiders) in on this flood-mitigation operation, too? If they slow down the rate of landfall through a raindrop catch-and-release system, maybe they give their roots more time to slurp up every drizzle that eventually finds its way into the soil?

An ornamental grass – maybe prairie dropseed (Sprorobolus heterolepsis)? – dressed up as a crystal chandelier.

If any scientists out there have explanations for these foliar-aquatic collaborations, please share them in the comments. Meanwhile, I’ll go with the theory that the plants are simply reveling in the refreshment of a long-awaited shower. The bedazzlement is their botanical version of Gene Kelly's singing, dancing and "laughing at clouds, so dark up above." What a glorious feeling!