Trees & Shrubs of the Eloise Butler Wildflower Garden

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. 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 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 inflorescence is a compact, pyramid shaped 8 inch high panicle of short stalked flowers at the end of the branches. Stalks of the inflorescence may have some fine hair.

The flowers are usually separate by sex, rarely perfect. The small 5-parted flowers are greenish-yellow with 5 sepals to the calyx with the lobes opposite the petals. The 5 petals are widest in the middle, have bluntly rounded tips and reflex when the flower opens. The staminate (sterile) flowers have 5 stamens placed alternate with the 5 petals. The filaments are yellowish green, the anthers yellow, oblong, with 2 cells. The sterile flowers have a smaller but imperfect ovary. The fertile flowers (pistillate) have a larger ovoid 1-celled ovary with 3 short styles. Fertile flowers usually show stamens that are functionally sterile and shorter than those in the staminate flowers. At the base of the ovary but not attached to it, in both sterile and fertile flowers, is a yellow to reddish nectary disc.

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.

 

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. Thickets are established from root sprouts from a vigorous root system. Fire and cutting encourage more growth, but short of using chemicals, fire is the most effective control.

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 currently accepted species name, typhina, is a obscure reference. In previous years the species name hirta was used which word refers to hairy roughness. But all the major authorities including USDA and the Minnesota Herbarium now use typhina. The author name of the plant classification - '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.