Sunday, August 18, 2013

Butterfly Peas and Bumblebees

Since its inception almost exactly one year ago, Hoot Owl Karma has become a true family affair. Brother Henry and Papa Jim, mentors and dedicated naturalists with a strong conservation ethic, have become strong advocates for the blog, sharing it with friends and kindred spirits and calling in tips from time to time. Several weeks ago, Henry alerted us to the presence of an impressive colony of butterfly pea along a rural roadside near his home in Harnett County, and Papa Jim called in with an update this week urging us to come by soon. 

Saturday morning dawned drizzly and gray, but Jay and I knew this might be our only opportunity to capture the short-lived spectacle before hectic upcoming weekend schedules and the impending school year intervened, so we boldly set out into the misty rain. 

And we were not disappointed!
Just a few hundred yards from my mother's ancestral homeplace, this is an impressive colony indeed. In my youthful ramblings throughout the area, I frequently encountered isolated single vines of butterfly pea, a foot or two in length and typically sporting just two or three of their lovely large lilac blossoms. Here we found dozens of vines, with hundreds, perhaps even thousands, of blossoms.
 The blossoms resemble many of their kin in the family Fabaceae, including the familiar cultivated garden peas, butter beans and green beans that grew in our childhood gardens; not to mention the native redbud and black locust trees featured in previous Hoot Owl posts.

The light rain coated the foliage and petals, creating a unique viewing and photo opportunity in spite of the sun's absence. 

The pea vines surmounted every manner of living thing on the high ditch bank where they grew, mingling with other vines and advancing their tendrils up the slender trunks of the sassafras saplings and pokeweed plants as well,

contributing a hint of autumn color to match the fall-like weather. 

While attempting to capture the brilliant red of the sassafras leaf, we were treated to a glimpse of the unusual and striking sassafras fruit, foodstuff for a variety of fowl, including the bobwhite quail.

As though entranced by its brilliant scarlet hue, the lens lingered long on the leaf before returning its focus to the blossoms of the butterfly...

Centrosema virginianum's most common name, butterfly pea, derives not from a pollinator relationship with the ephemeral winged denizens of recent Hoot Owl posts, but from the shape of the blossom itself, thought by many observers to resemble a delicate lavendar butterfly. 

Right on cue its real reproductive ally, the bumblebee, buzzes into view. A strong flyer, undeterred by a few drizzly drops of falling dew, the yellow-striped abdomen distinguishing it as a true bumblebee, not its cousin the carpenter bee of spring red bud fame, the pollinator arrives on the scene. 

Upon closer inspection, the flower structure works brilliantly to the plant's reproductive advantage. In order to access the pollen and nectar they need, the bumblebees must go "under the hood" located in the center of the blossom.

Underneath the hood-like projection, the reproductive organs of the plant are perfectly positioned to ensure that the bee receives a generous dusting of pollen while feeding. Furthermore, the "butterfly wings" of the mature blossom are perfectly angled to provide a foothold for the bee as it pauses to feed.

As it burrows deeply into the heart of the flower, the flexible "hood" allows the bee full access to the nectar without damaging the flower.

A quick aside...Here one can see that the trifolialate leaf structure of the butterfly pea is remarkably similar to that of the poison ivy with which it shares its roadside thicket. The old adage, "leaves of three, let it be" is apparently not quite as straightforward a proposition as we might have thought. Perhaps we should append, "unless its a pea!"

Now back to the bees...Oblivious to its invaluable role in plant reproduction, this bumblebee gleans what food it can from the blossom at hand, while collecting a healthy coating of pollen with the hairs on its back...

then heads to a neighboring blossom 

where it will feed again, and deposit a dose of diverse genetic material on the reproductive organs of the nearby vine, doing its part to ensure the future survival of another of North Carolina's fascinating native plants, the butterfly pea.

Special thanks to Jay and his steady hand for the bumblebee pics!

Karma Note: Thanks to the savvy reader who pointed out that we had initially mis-identified our butterfly pea. It appears that our colony consists of spurred butterfly pea, Centrosema virginianum, while the smaller vines I recall from childhood were quite possibly Clitoria mariana, or simply butterfly pea. Both plants are natives of our area. Thanks for the tip, and keep them coming!

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