Plant Confusions: Garden Sage and Sagebrush are Different

garden sage, Salvia officinalis

big sagebrush, Artemisia tridentata

Sometimes two plants with the same name are quite different. 

     I still remember my surprise, years ago, when I realized garden sage and prairie sages were unrelated.

    The culinary herb, sage, sometimes called garden sage for clarity, Salvia officinalis, is from Europe. Although it doesn’t taste or smell minty, you can call it a mint because it is in the mint family, Lamiaceae. It is related to a host of important culinary herbs, not just clary sage, spearmint and peppermint, but also plants as diverse as lemon balm, catnip and oregano. 

garden sage with flowers

  Members of the mint family can be recognized by the combination of a square stem and aromatic leaves, both of which garden sage has. No other plant family has square stems and aromatic leaves. Flowers of all mint family plants are similar in structure, if you look closely. 

garden sage relative: clary sage

garden sage relative: spearmint

    

garden sage relative: oregano

    In the US, sage is also the name of a group of native plants, also called sagebrushes or sageworts. These are plants in the genus Artemisia, a large genus in the daisy and ragweed family, Asteraceae (also called Compositae).  Common American artemisias include prairie sagewort A.  frigida. big sagebrush, A. tridentata, and Louisiana sagewort, A. ludoviciana. There are 37 species of Artemisia native to the lower 48 states, and another 7 in Canada and Alaska. They are herbs and low shrubs of dry regions with aromatic leaves, some pleasant to smell, some not. Like other members of the aster family, what looks like a flower is actually a group of tiny flowers. The artemisias are wind pollinated, so the flowers are inconspicuous and usually the color of the leaves. (Note that, although the leaves are aromatic, the stems are not square).

white sagewort or Lousiana sagewort Artemisia ludoviciana

prairie sagewort, Artemisia frigida

     Garden sages’ closest relatives are mints, prairie sages’ closest relatives are ragweeds and asters. Probably settlers called the American plants sages because the leaves of many species smell similar to garden sage.

     The curious thing, in addition to the name confusion, is that America has other close relatives (members of the same genus, congeners) of the European sages and Europe has other congeners of the American sages.  In America, closely related to garden sage are at least 47 native Salvia species (out of at least 959 worldwide). None of the American species are eaten as far as I know, but they are attractive plants and are frequently planted. Among those available to gardeners are Salvia azurea, azure blue sage, native to the plains states, and, from the U.S. Southwest Salvia farinacea blue salvia, Salvia dorii purple sage, and S. arizonica indigo blue sage. 

Salvia on the roadside in Mesa Verde National Park, CO, possibly S. henryii

    In Europe, closely related to the artemisias of the America plains and deserts are a series of important culinary or medicinal herbs, in particular wormwood Artemisia absinthium, mugwort, A. vulgaris, and southernwood A. abronatum.  An Asian artemisia, Artemisia annua, called sweet Annie or sweet sagewort in English and qinghao in Chinese is widely used in  Chinese medicine.

    North American tribes used the American Artemisia species in their regions for medicine so using an American Artemisia in a recipe that calls for sage is probably not a good idea. While I can find no reports of sagebrush poisoning of people, they are not considered safe to eat. I’d advise using the wild American sagebrushes and sageworts for incense and putting garden sage on your chicken.

References I consulted 

Gruenwald, J., T, Brendler and C. Jaenicke, editors. 2007. PDR (Physician’s Desk Reference) for Herbal Medicines. 4th edition. Thompson Healthcare Inc, Montvale, NJ.

Kershaw, Linda. 2000. Edible and medicinal plants of the Rockies. Lone Pine Publishing, Edmonton Alberta.

Kindscher, Kelly. 1992. Medicinal wild plants of the prairie. University of Kansas Presses, Lawrence KS.

Lewis, Walter and Memory Elvin-Lewis. 2003. Medical Botany. 2^nd ed. John Wiley and Sons, Inc., New York. 

USDA Plants database. Artemisia, Salvia  http://plants.usda.gov/

Kathy Keeler

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