small logoThe Friends of the Wild Flower Garden, Inc.

Plants of the Eloise Butler Wildflower Garden

The oldest public wildflower garden in the United States

Smooth Sumac

Common Name
Smooth Sumac

 

Scientific Name
Rhus glabra L.

 

Plant Family
Sumac (Anacardiaceae)

Garden Location
Upland

 

Prime Season
Early Summer flowering - Autumn fruit

 

 

Smooth Sumac is a native large shrub that given space, can become a small tree, 10 to 15 feet high. When growing in thickets, the tallest stems will be at the back with decreasing stem height forward, providing sunlight to all plants.

The alternate leaf is 16 to 24 inches long, pinnately divided into 11 to 31 leaflets, very pale underneath, dark green above, and often toothed. The leaf stem (rachis) without fine hair. Leaflets are narrowed or rounded at the base, sharply pointed at the tip. Unlike Staghorn Sumac, twigs are smooth, have spots and are not hairy. The leaves in the autumn turn a brilliant red and may often be seen turning color in late summer.

The flowers are usually separate by sex and form in a compact, pyramid shape 8 inch high cluster at the end of the branches. The small 5-parted flowers are greenish-yellow.

Fruit will appear on plants 3 to 4 years old. Smooth Sumac and Staghorn are very similar in that the flowers mature in late summer into a red hairy fruit 1/8 to 1/4 inches in diameter, called a drupe, which contains one ellipsoid shaped, slightly flattened, greenish-tan hard seed. A cluster may contain 100 to 700 seeds. Most plants contain only male or female flowers, thus only the female plants will produce seeds, although some plants may have both flowers. The fruit clusters, if not eaten in season will often be visible over winter and in spring before leaf out, thus providing winter interest.

 

Habitat: Sumac habitat is usually open fields and roadways, where there is sunshine and the soils are not wet. It will be crowded out by trees and larger shrubs. Sumac fruit is a winter emergency food for large game birds and many songbirds have sumac in their diet. Deer will browse the stems and fruit. Thickets are established from root sprouts from a vigorous root system. Fire and cutting encourage more growth, although those are also the two best control mechanisms short of chemicals.

Names: The genus Rhus is the Greek name for one species of this genus. The species name, glabra, is Latin for "smooth". The author name for the plant classification, 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.

Comparisons: There are three sumacs in the Garden - Compare: Staghorn Sumac, whose twigs have dense fine hair, but no spots - and Fragrant Sumac which has much different leaves and flower clusters.

See bottom of page for notes on the Garden's planting history, distribution in Minnesota and North America, lore and other references.

Smooth Sumac Green Flower head Smooth sumac flowers Smooth Sumac Fruit

Above 1st photo - The green flower buds and 2nd photo - flower cluster of late May to Mid June. 3rd photo - The drupes formed in July with their red acid hair.

Below: Smooth Sumac can be trained and pruned to produce a nice shrubby plant cluster (1st photo)- full sun only though; native form shown in the 2nd photo. 3rd photo - A cluster of drupes in April that carried thru the winter.

landscape plant native plant Smooth sumac prior year fruit
Smooth Sumac Smooth sumac twig Smooth Sumac Twig

1st photo Above and below: The characteristic leaf structure of Smooth Sumac. 2nd photo above - The smooth spring twig with new growth. Staghorn sumac would have hair on the twig and no spots. 3rd photo above and 2nd photo below: The smooth leaf stems and the spotted twigs.

Smooth Sumac leaf Smooth Sumac twig

Below: Each hairy drupe contains one ellipsoid shaped, slightly flattened, greenish-tan hard seed.

Seeds

Notes:

Notes: Smooth Sumac is indigenous to the Garden Area; Eloise Butler cataloged it on April 29, 1907. She planted two plants on May 15, 1914, obtained from her source in Boulder CO. It is native to all of North America from the lower Canadian Provinces down throughout the lower 48 states. In Minnesota it is found in most counties with the scattered exceptions being mostly in the western half of the state. It was listed on Martha Crone's 1951 Census of Garden plants and on all later census reports. The red berries can be used to make a drink along the likes of lemonade. The fruits have an agreeable, acidic taste when the mature fruit is washed briefly in water, then placing them in drinking water and crushing them with a spoon. Strain the liquid through a cloth to remove the hairs and seeds, add sugar to taste. The fine hairs contain the acid so they must be present in the crushing stage. The resulting beverage does not keep so make and use. (Ref. #9)

References and site links

References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.

©2015

071315