Sunday, October 12, 2008

Downy gentian

By mid-October, the tall, charismatic grasses of glades, prairies and woodlands have matured to a uniform khaki. Gleaming burgundy and pale green back in July, big bluestem now looks like Indian grass, like gama grass, like side oats gramma, with only the tripartite seedhead distinguishing them from the rest. Most blooming plants have already set seed, offering only a blackened stem and desiccated seedheads to anyone wanting to discover how rich and diverse a certain area is, leaving June's colorful floral display to the visitor's imagination.

But nestled between the clumps of grass, mostly on glade edges and prairies, downy gentian blooms from September through November. Low to the ground, this exquisite flower is one of the last ones to bloom in the Ozarks, reportedly even surviving early frosts. Spotty populations are common in the Ozarks, particularly in areas managed with fire. Thanks to the tremendous rainfall this growing season, I've seen clumps of blooming downy gentian repeatedly this fall, though its allure never fades; I crouch down to stare deeply into the iridescent blue flowers every time I see them.

Just as there are indicator plants whose presence suggest past and present grazing history (like coral berry and Eastern red cedar), the absence of certain plants also indicates grazing pressure, whether historical or current. Likewise, the presence of certain plants indicates a healthy balance between fire, grazing, hydrology, and every other factor that determines biodiversity in the landscape. Downy gentian happens to be a choice plant for grazers and browsers, so areas with too many large herbivores in the landscape may either lack populations of the elegant flower or have largely diminished populations of them. (And, conversely, areas rich with downy gentians likely have other conservative species) Coneflowers, prairie clovers, gentian, native Euonymous shrubs and countless other (now conservative) plants possess certain qualities that make them highly desirable to large herbivores. Where grazing pressure is high, these plants -called "ice cream plants" to some- are grazed to the nub, making their populations less viable every season.

Knowing that cattle intensely grazed every inch of the Ozark Highlands within the past 100 years, it's hard to tell whether the spotty populations of downy gentian are naturally occurring or just what the cattle left behind. Nevertheless, the plants hang on, blooming intently for the next month...even after a frost.


John said...

Wonderful blog! A friend directed me here last week, and I just might get addicted.

Thanks for the downy gentian entry. I spotted my first one last Wednesday afternoon on a wee bluff-top glade overlooking Clifty Creek (in Maries County). It was on the inside corner of a switchback turn I built two years ago. I remember disturbing quite a bit of dirt/gravel on that turn, so it's been nice to see plant growth returning on everything but the foot path.

Do you think that the soil disturbance helped or hindered the downy gentian?

Allison Vaughn said...

Thanks for reading. I never know who reads this until I get mail, so...thanks! Is downy gentian known from Maries? While gentians and most other glade endemics appreciate the disturbance of fire, soil disturbance like deep trail building normally only invites little weedy things like beefstake plants. (In the case of shortleaf pine, soil disturbance by elk, for example, is necessary. It really depends on how you built the trail...light disturbance can be good for wildflowers in general...However, this year in particular has been great for wildflowers thanks to all the rain, so maybe it was there all along? You're making me want to write about soil disturbance again.)