Why do bluebonnets turn white, red or maroon?

With all the attention given to genetically modified plants these days, it’s easy to forget that there is more than one way that we end up with genetic variants within species.

Plants have been procreating since long before humans arrived on the scene, and subsequently, humans have taken note of this natural tendency and intervened to create more of any particular genetic trait that we happen to fancy.

We all remember from school how offspring get half their genes from each parent, and white or red Lupinus texensis are no different. Non-blue flowers are a recessive trait, so we don’t see them as often in wild populations.

And even if they are among out there, the sea of blue along a roadside dominates our eyes and makes those anomalous individuals harder to spot.

Now, let’s get back to man-made manipulation of those colors. When botanists spot oddballs in nature, they know they’ve found something unique, and being unique in the horticultural trade is normally a prized trait. In addition to the fairly rare white-flowering plants, there are also light pink and maroon bluebonnets. Sequestering these plants and forcing them to procreate only among themselves increases the likelihood of offspring with the desirable trait.

Of course, when enterprising Aggies discovered the maroon variant, they set about creating more of them, and making them available to the public, leading to a cultivar of bluebonnet named ‘Texas Maroon’.

But in your landscape, as by the roadside, those non-blue variants are fleeting, since cross-pollination is nature’s way of ensuring genetic diversity. Maroon, white, and pink-flowering plants in your yard will be easily pollinated by blue ones, and the dominant blue trait will return, with other colors popping up as rarely as they do in nature.

This of course brings to mind the sensational story from a few years ago, when a few maroon bluebonnets popped up among the native blue ones on the UT campus, prompting many Longhorns to suspect foul play. Although not impossible, it’s much more likely that the unique colors were just nature’s little trick!

And if you have a fondness for unique wildflowers, look for the Texas Super Star ‘Lady Bird Johnson Royal Blue’ cultivar next season. It’s a deep, vibrant blue.