Staghorn Sumac is a native shrub that usually grows in dense thickets, but given space can become a small tree, 30 to 35 feet high with a trunk of over 4 inches diameter. Twigs are densely hairy when young and without spots.
The alternate leaf is long, pinnately divided into 9 to 29 leaflets, pale underneath, dark green above, the leaf stem (rachis) with fine hair. Leaflets are narrowed at the base, pointed at the tip and with fine serrated edges.
The flowers form in a compact, pyramid shape cluster at the end of the branches. The small 5-parted flowers are greenish-yellow with a red center, which is ring of nectaries. The five stamens are yellow and are clustered around the style. Most plants contain only male or female flowers, thus only the female plants will produce seeds, although some plants may have both flowers.
Fruit: The flowers mature in late summer into a red hairy fruit 1/8 to 1/4 inch in diameter, called a drupe, which contains a single ellipsoid shaped, slightly flattened, greenish-tan hard seed. A cluster may contain 100 to 700 seeds. The fruit clusters, if not eaten in season will often be visible over winter and in spring before leaf out, thus providing winter interest. The leaves in the autumn turn a brilliant red and may often be seen turning color in late summer. When growing in thickets, the tallest stems will be at the back with decreasing stem height forward, providing sunlight to all plants. These thickets are established from root sprouts from a vigorous root system. Fire and cutting encourage more growth.
Habitat: 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. Sumac habitat is usually open fields and roadways, where there is sunshine and the soils are not wet.
Names: The velvet like hairy fuzz on new growth, like on a stag's horn, is the basis for the common name. The genus Rhus, is derived from the old Greek name for Sumac - rhous. The species name, hirta, refers to the hairy roughness. In previous times the classification was Rhus typhina L. The author name of the plant classification - ‘Sudw.', refers to George Bishop Sudworth (1864-1927) American Botanist, founder of the Society of American Foresters, Chief Dendrologist of the U.S. Forest Service, and whose most noted publication is A Check List of the Forest Trees of the United States. He updated the work of '(L.)' which 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: Smooth Sumac, (R. glabra) which does not have hair on the twigs and has spots on the twigs. Fragrant Sumac (R. aromatica ) has much different leaves and flowers.
Above: 1st photo - The dense pyramid shaped flower cluster. 2nd photo - Individual 5-parted flowers in the flower cluster. 3rd photo - The hairy red fruit (drupes) of late summer
Below: 1st photo - The pale underside of a leaf, this one with 17 of the possible 29 leaflets. 2nd photo - Beautiful fall color of the leaves sets sumac off from the surrounding vegetation. 3rd photo - The fruit cluster in late September has turned from a bright to a more subdued red.
Below: Detail of the individual drupes with their characteristic long reddish hair, containing an acid.
Below: Each drupe contains a single ellipsoid shaped, slightly flattened, greenish-tan hard seed.
Below - The beginning and the end: 1st photo - A spring twig showing the dense hair and a remaining cluster of drupes from the prior season that over-wintered. 2nd photo - The brilliant color of autumn leaves with ripe fruit.
Below: A grouping of Staghorn Sumac in late summer. When growing in thickets, the tallest stems will be at the back with decreasing stem height forward, providing sunlight to all plants.
These galls affect both Staghorn Sumac (Rhus hirta) and Smooth Sumac (Rhus glabra). Some writers state they see them most often on Staghorn but in my area they are always on Smooth Sumac. This rather large gall arises with a small aphid, Melaphis rhois lays an egg on the leaf underside. This causes the leaf to secrete material that forms a sac over the egg. Inside, a number of generations of aphids form and females leave the gall in late Summer where they lay eggs on a host plant and those eggs produce the aphids for the next seasons infestation.
John Muir wrote in 1911: Each species seems to know what kind of plant will respond to the irritation or stimulus of the puncture it makes and the eggs it lays, in forming a growth that not only answers for a nest and home but also provides food for the young." From his essay Mt. Hoffman and Lake Tenaya.
Below: 1st photo - a Smooth Sumac leaf with a number of galls. 2nd photo - Galls are large and frequently with reddish tints. 3rd photo - the inside of a gall with young aphids.
Notes: Staghorn Sumac is native to the eastern half of North America. In Minnesota it is found in most counties in the eastern half of the state, with scattered exceptions, such as Lake and Cook. You will see it in large stands along many metro freeways. Staghorn Sumac was not indigenous to the original part of the Garden, but it may have been to Wirth Park. Eloise Butler first reported planting it on Oct. 9, 1918 with plants sourced from Fort Snelling; again in Oct. 1919 sourced from Meadowbrook along the Luce Line RR and in Oct. 1920 from Minnehaha. It was also listed on Martha Crone's 1951 Census of Garden plants.
Lore: Densmore (Ref. #5) reports some use of the plant among the Minnesota Chippewa. A decoction of the flowers would be taken for stomach pain. Also, they would use the inner bark and pulp of R. hirta and R. glabra to make various yellow dyes. Mrs. Grieve (Ref. #7) also has many other details in her book.
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: 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.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"