texas

Bluebonnet Edition

Would Texas be the Texas we love so much in the spring without bluebonnets? Would we feel as Texan, be it multi-generational or newcomer without our shared springtime rite of highway passage? At High Hope, we eagerly watch for the telltale rosettes in the hopes of being awash in bluebonnets. I have always enjoyed pointing out that the newer florets (miniature flowers, each little ‘bonnet’ is a complete flower!) have a white spot, and the older ones at the bottom are reddish purple.

Before I indulge you in what I now know to be false information about our beloved bluebonnets, I want to share a quote that came from one of my favorite biologists and co-workers, Dr. Dede Armentrout. “The mark of a truly good scientist, is that after presenting their life’s work, they end with the simple statement, “But I may be wrong!” I have been wrong, in a cart before the horse sort of way, since 1983! What I have been erroneously telling people is that the color change occurred once the floret was pollinated! Turns out, they are just the bluebonnet’s version of age spots. 

Like all good biologists, I decided to do some research before I committed my pollinating beliefs to paper. I did a quick search on the biology of bluebonnets to find out what I could about the color change. Turns out, I could (and did!) spend hours reading about bluebonnet origin stories (I highly recommend the children’s book, “Legend of the Bluebonnet,” available in some of our guest houses!), myths of why some of them are pink, how after 70 years of political shenanigans we actually have five official state Texas flowers, all of them bluebonnets, where to see them and how to grow them and more.  

 What was more difficult to find was why the bluebonnet changes its spots. This is why I love science, particularly the science of nature. I believe if you are curious, you are never bored. Here is why:

Let’s start with some basic biology. The object of every living creature is to reproduce to sustain their population. Every species that requires genetic data exchange from a male to a female counterpart, has a mechanism to make that happen. Bluebonnets are called ‘out-crossers’, they need pollen from a different plant to produce seeds and continue their lineage for another season. Their pollen is delivered by bees.  

For bees, pollen (as opposed to nectar feeders like butterflies, hummingbirds, bats and other long-tongued creatures) is life, their food source. Bees will seek out pollen-rich sources, the more pollen they can get per visit, the less energy they must expend on getting their nutrition.  If they can somehow identify or find a pollen-rich source over a pollen-poor source, the pollen-rich plant will get more attention from the bee and have increased outcrossing success.

All of these years, I thought there was some sort of magical chemical reaction that happened after pollination to create the color change in the bluebonnet. In effect telling the bees they are no longer needed, don’t waste energy on this one little floret. There is magic, but it is more about aging than pollination, however there is a connection.  

In 1980, a study was done to see if the spots would change without being pollinated.  Pollinators were kept away from a plot of bluebonnets and observed carefully.  When each floret was five days old, it still started turning reddish purple, and was completely changed by day six. Along with that color change, the quality of the pollen, both for the bees and outcrossing success, was diminishing in time.  The still magical win-win around this color change is best described here.  Below is an excerpt:

“The interesting thing about Texas bluebonnets is the bright white spot on the banner (upright portion) of each floret. Bees are extremely attracted to these bright spots and can collect a large quantity of high-quality pollen from the florets. As the florets age, however, the white spots turn a purplish-red and the bees are much less attracted to them as a result. At the same time that the spot changes color, the pollen becomes less abundant, less fertile, and less sticky.

“This confluence of events just happens to be good for the bees and good for the plant. It is good for the bees because they can efficiently collect lots of nutritious pollen without having to expend energy checking the purple-spotted florets. In addition, the pollen is so sticky the bees can carry large loads of it back to their hives or nests.

“It is good for the plant because it means that the bluebonnets–which are dependent on insect pollinators–are pollinated with fresh, fertile pollen rather than with older, drier, and less fertile pollen. This, in turn, assures that a large crop of high quality seeds will be produced from the flowers. It is definitely a win-win situation–what we call a plant-pollinator mutualism.”

Looks like I’ll have a little more ‘splaining to do next time I get the chance to point out the changing spots on our bluebonnets!  We’ll be looking for rosettes on my February 20th “Lollygagging for Love” walk about the ranch and looking forward to the peak blooms from Mid-March to April. Catch the blooms in person by booking your stay at one of our houses, reserve a campsite, or sign up for a day hiking pass!