Friday, September 4, 2009

Gentiana rubricaulis

While working in Superior, Wisconsin a few weeks ago, we came across a gentian that I had never seen before, with dull grayish-blue closed flowers and a reddish stem. Upon running the plant through a key, we determined that we had found Gentiana rubricaulis, Red-stemmed Gentian.

Gentiana rubricaulis differs from similar species such as G. andrewsii and G. saponaria in having smooth-margined leaves and calyx lobes (as opposed to leaves and calyx lobes with ciliate margins). In addition, the plaits between the corolla lobes in G. andrewsii are longer than the lobes, while those in G. rubricaulis are shorter than the corolla lobes. Another important feature used to distinguish G. rubricaulis from similar species is that the the calyces and lower portion of the flowers are usually sunken within the involucral leaves. Finally, the leaves of this gentian are a lighter green color than those of most other members of the genus.

Sometimes referred to as Great Lakes Gentian, the distribution of G. rubricaulis is primarily centered around the Great Lakes; it is known only from four states (Minnesota, Wisconsin, Michigan, and Maine) and three provinces (Manitoba, Ontario, and New Brunswick) in North America. With an affinity for alkaline conditions, G. rubricaulis can be found in sedge meadows, bogs, fens, alder thickets, and coniferous swamps. The closed flowers are pollinated when bumblebees force them open in search of nectar and pollen.

The genus Gentiana was named after Gentius, the King of Illyria, who discovered that the roots of some members of the genus could be used to treat malaria. Rubricaulis is Latin for red stem.


Gayle said...

June 10, 2016 I am trying to identify a red-stemmed gentian growing at Apostle Islands National Lakeshore Visitor Center natives garden. It hasn't bloomed yet but will soon so I can photograph. I would appreciate help with ID. It has very blue, glaucous leaves. How can I post photo so you can help?

Scott Namestnik said...

No way to post here. Send me photos at Close-ups of flowers, and also of flowers pressed in your fingers so I can see plait to petal length ratio, will help.