Sunday, August 30, 2015

Plant Story--Gaura coccinea, Oenothera suffructescens, Pretty Native Wildflowers

Oenothera suffrutescens scarlet gauraWhat is that little plant?
Across most of the United States you can find it growing on sandy, disturbed sites. 

It is Oenothera suffrutescens, formerly Gaura coccinea, scarlet gaura, also known as scarlet bee blossom, butterfly weed, scarlet butterfly weed, gray scarlet gaura, wild honeysuckle, waving butterfly and linda tarde. 

Scarlet gaura is native to central North America, from Manitoba south to central Mexico. In addition it has been introduced and has escaped from California to Maine (at least) that so it is pretty much continent-wide in North America. In California it is a noxious weed.


Gaura coccinea now Oenothera suffrutescens
scarlet gaura, scarlet beeblossom, waving butterfly
In most of my photos, the flowers look white. Why is called scarlet? Well, part of each flower is scarlet, but in addition, as the flowers age they turn red, according to the plant manuals. But in my photos there are lots of flowers but no gradation of color. Other books just say the flowers vary in color from white to red in different locations.

The only studies I could find of pollination in scarlet gaura reported small moths (noctuids and geometrids) pollinated it. The name butterfly weed seems to suggest it is visited by butterflies but was  explained by Scotter and Flygate as "sometimes called Butterfly Weed because the 4 white-to-scarlet petals are twisted and move like wings in the slightest breeze" (p. 164). The sweet pleasant smell is described as being stronger at night. It is certainly pollinated by moths, but whether the plants are also pollinated by butterflies by day as red flowers suggest, no one says. (Generally night-blooming plants are pale to white in color, while reds appeal to day-flying animals especially butterflies.)

Oenothera suffrutescens formerly Gaura coccinea
Oenothera suffrutescens formerly Gaura coccinea
It is not toxic or strongly medicinal, so there aren't many Native American uses recorded. The Navajo made a cold infusion (tea) for children to settle their stomachs after vomiting. 

The Lakota reported they rubbed it on their hands to catch horses: apparently horses were curious about the smell and therefore let people get close. But scarlet gaura is a pasture weed which "has no forage value for livestock" (Nebraska Department of Agriculture p. 377). Why would horses find the smell of something both common on the range and inedible interesting? Perhaps horses really are attracted to the smell. But alternatively maybe the Lakota who was interviewed by the ethnobotanist was feeling playful and made up an answer for a plant that he or she didn't use. (Have you ever imagined being interviewed by a foreigner about each of the things in your house? How long would you stay serious?) A lovely use, if effective.  

Gaura coccinea now Oenothera suffrutescens

The plant's scientific name in all but one of my many books is Gaura coccinea. However, in 2007 a technical paper by Wagner, Hoch and Raven reconsidered the evening primrose family Onagraceae and as a result, rearranged all the gauras. They found Gaura coccinea to be an evening primrose and moved it into the genus Oenothera with the other evening primroses. The species epithet coccinea got left behind as well: now Gaura coccinea is Oenothera suffrutescens. Thus, searching for gaura on the USDA plants website sends you to Oenothera. 

One interesting consequence of the scientific name change is that it orphans the common name scarlet gaura. It made sense when the genus was Gaura. Now gaura is an just unfamiliar word to learn.  Considering alternate common names, the name butterfly weed has the problem that the milkweed Asclepias tuberosa, butterfly milkweed, a much better-known plant, is sometimes called butterfly weed (for example in Mammoser and Tekiela 2007) so we increase confusion by calling Oenothera suffrutescens butterfly weed. Wild honeysuckle links it to honeysuckles (Lonicera, they're shrubs and vines, honeysuckle family, Caprifoliaceae), to which it is not related. Scarlet beeblossom is better than those, but in this era of conserving pollinators, it is misleading name for a moth/butterfly-pollinated plant. I had never seen or heard the common name waving butterfly before I started researching this post, but I'll start calling it that. If I can learn a new scientific name I can learn a new common name to go with it.

Gaura coccinea now Oenothera suffrutescens

In Colorado, waving butterfly is native and makes an attractive water-efficient garden plant. In moister areas, it sometimes grows too well. (One person's weed is another person's beautiful flower. --I think that is actually a garden truth.)

If you don't grow it, enjoy it when you see it, it is widespread in North America. Since you noticed it, look to see if there are day-time flower visitors.  Butterflies? Bees? 

And if you can offer it to horses, let me know what they do.

Comments and corrections welcome.

References
Mammoser, D. and S. Tekielko. 2007. Wildflowers of Colorado. Field Guide. Adventure Publications, Cambridge MN.
Moerman, D. E. 1998. Native American Ethnobotany. Timber Press, Portland, OR.
Nebraka Department of Agriculture. 1995. Weeds of the Great Plains. University of Nebraska Press, Lincoln. 
Scotter, G. W. and H. Flygate. 2007. Wildflowers of the Rocky Mountains. Whitecap Books, Vancouver. 
Wagner, W. L. P. C.Hoch, and P.H. Raven. 2007. Revised Classification of the Onagraceae. Systematic Botany Monographs. 83: 1-240. 
Young, H. 2014. Wildflowers and other plants of the Larimer County Foothills Region. Larimer County Natural Resources, CO. 


Kathy Keeler



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