Sunday, August 25, 2019

Plant Story--Pleated Gentian, Gentiana affinis

pleated gentian, Gentiana affinis

This pretty plant is the pleated gentian (Gentiana affinis, gentian family Gentianaceae). Also called Rocky Mountain gentian, bottle gentian and prairie gentian.

The gentians are a family of some 99 genera and 1,750 species found all around the world. The family is named after Gentiana, a big genus of 400 or more species, also native worldwide. Thirty gentian species are native to North America.

The name gentian is based on Gentius, an Illyrian king in the western Balkans (reigned 181-167 BCE, biography), who reportedly used the yellow gentian, Gentiana lutea, to successfully treat his soldiers. The species epithet of the pleated gentian, affinis, means "related to" or "similar to." That seemed an odd name until I tried to check the identification of the plant pictured above, a plant I've grown for years. Western wildflower books described it as very similar to Parry's gentian (Gentiana parryi) and eastern plant books called it very similar to the downy gentian (Gentiana puberula). None of the common names of pleated gentian are very distinctive since there are other gentian species that are also called mountain, bottle, and prairie gentians.

In nature the plants make a dramatic discovery:
gentian, White River National Forest, CO
Gentian, White River National Forest, CO
Pleated gentian is described as very variable and the photos on line and in my books include reddish stems and mostly green stems, open flowers and closed flowers, distinctly purple flower to blue ones, small and large clusters of flowers at the top of the stem, single shoots to clumps of flowering stems. I suppose that is reasonable for a plant found across the western half of North America and across a wide range of habitats and elevations. (USDA map).

Some bottle gentians never open their flowers, in the sense that the flower is mature and ready for pollination but still looks like a bud. I was bending over a bottle gentian in a Nebraska prairie when the bumblebee that had climbed inside to pollinate climbed out, right under my nose, to our mutual surprise. (Nice photo link) There, I watched the big bumblebees cruise above the grass, suddenly dropping out of sight when they spotted a bottle gentian.

Pleated gentian is rather closely related to those ever-closed bottle gentians. The Colorado wildflower books say its flowers stay closed unless in bright sunlight but I often see flowers open in light shade.

pleated gentian, Gentiana affines

In my yard it is very tolerant of light conditions and has formed big clones in deep shade, partial shade, and full sun. That's both bad and good, because it quickly expands to crowd neighboring plants but makes a spectacular display when blooming. Flowering starts for me, close to but not in its natural range, in June and can continue all summer.

While not as specialized for bumble bees as the closed bottle gentians, this and other gentians are very attractive to bumblebees, as well as other bees.

Gentian is a familiar herbal name because yellow gentian, Gentiana lutea, of Europe, has been used for digestive issues including gas, diarrhea, heartburn, loss of appetite and vomiting since Roman times. Compounds of the roots were used for all those applications and others, and it was applied to the skin to treat wounds. Modern research has found it effective for dyspepsia, loss of appetite and flatulence. People also liked yellow gentian's bitter taste and put it in beer, wine, and vermouth (examples), bitters (Stockton, Angostura and more) and various foods (examples).

The American gentians were not much used by Native Americans. The pleated gentian (Gentiana affinis) was used for headaches (taking it as snuff), as a stimulant for fainting and as an antidote to witchcraft by the Navajo. The Blackfoot decorated with the handsome flowers. Western foraging books sometimes say American gentians can be used as a stomach tonic like the yellow gentian. Most if not all species are toxic in large quantities, but very very bitter so unlikely to be overeaten. Go with care if it isn't the yellow gentian, Gentian lutea, because plants in a large genus can be very different in chemistry.

We don't have to have a use for a plant to enjoy it. Whether you find it on a hike or grow it in your garden, the pleated gentian is a beautiful native North American flower.

pleated gentian, Gentiana affines
pleated gentian in the garden

Comments and corrections welcome.

Ackerfield, J. 2015.  Flora of Colorado. BRIT Press, Texas.
Barkley, T. et al. 1986. Flora of the Great Plains. Great Plains Flora Association, Lawrence, KS.
Gaia Herbs. Gentiana lutea Gentian link Accessed 8/20/19
Gentain Research Network. All things gentian. Looks academic but has some great lists, for example link  Accessed 8/20/19
Kershaw, L. 2000. Edible and medicinal plants of the Rockies. Lone Pine Publishing, Auburn, WA.
Moerman, D. F. 1998. Native American Ethnobotany. Timber Press, Portland OR. Online link
Moore, M. 2003. Medicinal plants of the West. Revised and expanded edition. Museum of New Mexico Press, Santa Fe.
PDR for Herbal Medicines. 2007. Yellow gentian. 4th Ed. Thomson Publishers, New Jersey.
WebMD. Gentian. link. Accessed 8/18/19.

Kathy Keeler, A Wandering Botanist


  1. Hello, I stumbled into here via searching for what this flower was.. I bought a small pot couple years ago at a garage sale- plunked them in..I LOVE them, I love ALL heirloom flowers that actually are of use to the bees and butterflies, etc! And OH boy does this flower spread! I did not mind, I merely keep digging out any around the edges where I don't want them! Then, I plunked those into the woods around me. And OH my I am rewarded now with those in the woods. Lovely flower. Now I know what it is I have! Gramma Deb

  2. Those pictures are not gentians. That's Campanula glomerata. Also loved by bees!

    1. I think you are right. I have identified this plant--it was in my yard when I bought i--as several different plants over the last decade. I THOUGHT I finally had it right, but apparently not. I'll check the details and then correct the blog. Thanks.