In Bloom: A bluebell of a different color

SNOWMASS VILLAGE ” Another wildflower season is under way, with about 70 species gracing the Roaring Fork Valley at last count and another half-dozen or so blooming each day. The usual early bloomers ” the mustards, the “weedy” annuals, and the sage and sun-loving borage, phlox and paintbrush ” arrived a week or two earlier than last year, and a week or two later than the year before, in what appears thus far to be a “normal” start to the wildflower season.

What exactly is “normal” was a question that came up on a hike Tuesday on the ridge-top road above the Highline Trail in Snowmass Village, where a bright white, sage bluebell plant (Mertensia oblongifolia/fusiformis) stopped me in my tracks. I’ve seen white versions of purple larkspur and a few other wildflowers before, but never of sage bluebells.

The answer to why these particular bluebells were white, when 99.9 percent of bluebells are not, neatly encapsulates Darwin’s 150-year-old theory of evolution by natural selection, as well as the genetic discoveries since that have fleshed out Darwin’s theory and turned it into fact.

First, we now know that white, or “albino,” versions of flowers can result from mutations in one or more genes that control the development of pigment. These mutations occur spontaneously and infrequently, like most other genetic mutations, some of which, because they cause no harm to the plant or by chance improve the plant’s fitness in its environment, get passed along and eventually, with the accumulation of other mutations, lead to entirely new forms.

These “endless forms most beautiful and most wonderful,” as Darwin called them, are the 70 species of wildflowers ” and the hundreds more to come this summer ” decorating our mountainsides. From the splashy bouquets of yellow balsamroot to the impossibly delicate, white woodland stars on display now, all are the result of random genetic mutations, just like those that turned the bluebells white, and which will lead to flowers we haven’t even begun to imagine.

The future of the albino bluebells, however, is not as promising. Certain pollinators, in this case bees, have learned to associate the bluebells’ distinctive size, shape and especially color with a nectar reward. If the bluebell loses its color, it may not be as easily recognized or as attractive to the bee, and may be passed by. Without bee visits, cross-pollination won’t occur and the plant won’t reproduce.

This likely explains why I’ve never seen a white bluebell before, and why, aside from this little jewel above Brush Creek, I might not again. What is certain, however, is that thanks to the mutability of genes and the power of evolution, wildflower lovers can always look forward to more spring surprises.