Plant Story -- Smooth Sumac, Rhus glabra

Sumacs are common shrubs in North America, and inconspicuous except in the fall, when the leaves turn a brilliant red. 

 

Sumacs are in the genus Rhus in the cashew family Anacardiaceae. Currently about 50 species of Rhus are recognized, mainly north temperate shrubs. The USDA plants data base lists 19 species and two hybrids in the United States and Canada. Most have a limited distribution. Five species are found in more than four states: fragrant sumac, Rhus aromatica, smooth sumac Rhus glabra, skunkbush sumac, Rhus trilobata; staghorn sumac, Rhus typhina, winged sumac, Rhus copallinum. This post focuses on the most widespread, smooth sumac. Smooth sumac is found from the Atlantic to the Pacific in North America and although native, is aggressive and often invasive.

 smooth sumac, Rhus glabra 

 

Telling smooth sumac from other common sumacs is not difficult. It has the compound leaves with 7 to 23 paired leaflets, which I think of as characteristic of sumacs. Aromatic sumac and skunkbush sumac have leaves in groups of three, not those long compound leaves. Winged sumac has wings, a line of green tissue along its various stems, the others do not. Finally, staghorn sumac is very hairy, while smooth sumac has tiny hairs on its fruits, but no long white hairs all over the stems. And of course, being so widespread and aggressive, smooth sumac is generally easier to find. 

Smooth sumac grows rapidly to fifteen feet tall. The plants are dioecious, that is, some plants produce only pollen and others with ovaries that develop into the fruit; thus two plants are needed for seed production. However, smooth sumac sends out root suckers that will go underground for ten feet or more, letting it form a clump, or in the case of my garden, pop up at the far end of the flowerbed.

Rhus is the Greek name for a European sumac. The species epithet glabra means smooth or hairless. The species epithet typhina means "like typha"; the namer saw a resemblance to cattails in the seed heads. The other species epithets can be explained as follows: aromatica means scented or aromatic, copallinum means resinous and trilobata means three-lobed, that is the leaves have three lobes. 

The plant family Anacardiaceae is justly famous for its toxic plants. In particular, poison ivy (Toxicodendron) is in the Anacardiaceae. Cashews (Anacardium occidentale) are also in the family; they are poisonous unless cooked. And you have probably heard of poison sumac (Toxicodendron vernix). 

Despite all their dangerous relatives, all the sumacs, genus Rhus, have edible fruits and shoots. 

Poison sumac has a leaf form that resembles smooth sumac, but the fruits are whitish green and hang down like grapes. There are other differences in the leaf details, habit, and habitat; if you live in the southeast where poison sumac grows, be sure you can recognize it. 

sumac, Rhus, fruits

 

The fruits of smooth sumac are small seeds surrounded by a hairy red covering. Steeped in water, sumac fruits make a "lemonade" that is as widely liked as lemonade made from lemons. Successful preparation means getting freshly ripened sumac berries, not ones that have been on the plant all winter. See Samuel Thayer, The Forager's Harvest for excellent advice. He also cooks the young shoots, after pealing off the outer layers. These uses apply to the other red-fruited sumacs (Rhus), though some are better than others. 

 

sumac, Rhus, fruit

  

(I am not certain the fruits shown are smooth sumac not staghorn sumac. Staghorn sumac's new shoots have long white hairs "like the fuzz on a stag's horn" and it is hard to make out the details in my photos, which are from Michigan, Nebraska, and Colorado.)

 

Despite its tendency to spread, sumac is a cool plant to grow in the yard. It is tough and drought-resistant. The flowers are yellow or cream colored and buzzed with small bees, flies, honeybees and even bumblebees. See what the flowers look like here (wikipedia) link. In the fall, sumac leaves turn an intense beautiful red. (See first photo, above).

 

In the prairies of the Midwest, sumacs grow at the edge of forests, shaded out by taller plants.  But they shade out plants themselves, in particular the prairie grasses. Fires, in our case prescribed burns on Nebraska prairie remnants, pushed the sumacs back. However, the clumps were deep enough that it took several fires in successive years to kill them, otherwise the clump quickly regenerated from the ones in the center that the fire did not reach. 

 

Sumac clump in meadow in summer

 

All across its range, Native Americans used smooth sumac as a food, mouthwash, burn dressing, dye plant and much more: Native American Ethnobotany has more than 100 entries for it (link). Smooth sumac was an important resource.

smooth sumac, Rhus glabra

It is the host plant for a number of native insects, attractive to pollinators (cool pictures link) and the fruits are important food for birds and small animals, especially into the winter when other foods become scarce.

Notice their glorious contribution to the colors of autumn!

 

Comments and corrections welcome.

References

Moerman, D. E. Native American Ethnobotany database link (Accessed 10/25/25)

Smooth sumac vs. staghorn sumac bplant.org https://bplant.org/compare/1227-1228 (Accessed 10/22/25)

Stearn, W. T. 1996. Stear's Dictionary of Plant Names for Gardeners. Cassell Publishing. London. 

Thayer, S. 2006. The Forager's Harvest. The Foragers Harvest Press, Birchwood, Wisconsin.  

 Kathy Keeler, A Wandering Botanist
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