Ohio Perennial and Biennial Weed Guide

Family:

Cashew Family (Anacardiaceae)

Other Names:

Rhus hirta, staghorn, scarlet sumac, upland sumac, velvet sumac.

Origin and Distribution:

Staghorn sumac is a native of eastern U.S. with a current range extending north to Quebec, south to Georgia, and as far west as Iowa. It grows everywhere in Ohio except a few counties located in the central and west central parts of the state. Staghorn sumac establishes on clearings, hillsides, open woods, and disturbed areas such as roadsides and reduced-tillage fields. It was planted as an ornamental but escaped cultivation, so it can also be found growing in lawns and gardens. The plant tolerates unfavorable conditions, thrives in polluted city air, and grows in such inhospitable sites as cracks in pavement. It will grow on any soil type.

Plant Description:

This deciduous, woody perennial grows in a colony as a shrub or it may grow alone as a small tree. Staghorn sumac has compound leaves that can grow 12 to 24 inches long and are composed of many 2- to 5-inch-long leaflets. Leaflets turn bright colors before falling off in the fall. The appearance of its branched stems, which are covered with soft hairs, resembles that of deer's antlers. Red fruits form in dense, upright clusters that look like hairy cones located at the tips of branches. Reproduction is by seeds and rhizomes (horizontal underground stems).

• Root System:

  Root systems tend to be shallow and wide-spreading.

• Seedlings and Shoots:

  Young shoots have thin, dark-brown bark and are densely hairy.

• Stems:

  Trees can grow over 30 feet tall but usually do not exceed 15 feet. Stems are generally between 2 to 4 inches wide, but plants with diameters as great at 15 inches have been recorded. Bark is smooth and dark brown. Stems are covered with long, soft hairs and exude a milky sap when cut. Branches display U-shaped leaf scars in winter.

• Leaves:

  Leaves are alternate (1 leaf per node) and compound with between 9 to 31 leaflets. Leaves are between 12 to 24 inches long. Leaflets are located opposite each other with a single leaflet located at the tip of each leaf. Leaflets are 2 to 5 inches long, shaped like oblong lances, and have coarsely-toothed edges. In summer, leaflets are dark green above and paler green below. In fall, they turn a range of colors from orange to scarlet to purple before falling off. Leaves attach to stems by way of hairy stalks (petioles) and the stalks attached to leaflets are also hairy.

• Flowers:

  Small green flowers form 8-inch long, pyramid-shaped clusters located at the end of stems. Male and female flowers are located on separate trees.

• Fruits and Seeds:

  Fruits are red, berry-like, hard, and covered with long hairs. Fruits form in erect, cone-shaped clusters at the tips of branches. Clusters are so compact they look like hairy cones. Fruit may persist until spring.

Similar Species:

Dwarf sumac (Rhus copallina) is similar in appearance except its stems have raised dots and its leaflets have smooth edges. Smooth sumac (Rhus glabra,) can be distinguished from staghorn sumac by the lack of hairs on its stems and petioles. Naturally occurring crosses between staghorn and smooth sumac result in hybrid offspring with characteristics intermediate between those of both parents. Characteristics of poison sumac (Toxicodendron vernix), which causes dermatitis in sensitive individuals, distinguishing it from staghorn sumac are white hairless fruit, hairless stems, and smooth-edged leaves. Leaves of tree-of-heaven (Ailanthus altissima) are also compound but their leaflets have 1 to 2 teeth located near the base compared to staghorn sumac leaflets that have numerous teeth all around the edge.

Biology:

Flowering begins in June and continues through July. Many species of birds have been observed eating the fruits of staghorn sumac, especially during the winter months. As a result, seeds are frequently dispersed by birds. Because plants spread by rhizomes, an area can become populated by many related plants with overlapping crowns that give the appearance of a dense colony with an extensive rounded or flat top. As colonies enlarge, older plants tend to be located in the center and younger plants emerge around the ever-expanding parameter.

Toxicity:

None known. However, the cashew family also includes poison ivy, poison oak, and poison sumac. Persons sensitive to these other plants should be cautious around staghorn sumac.

Facts and Folklore:

• 'Staghorn' refers to the appearance of the branches of this species, which are covered with soft hairs resembling that on a deer's antlers when 'in velvet'.

• The Latin name used to distinguish this species refers to the manner the hairy, dense clusters of fruit located at the tips of branches resembles 'Typha' species (cattails).

• Native Americans used sumac as an antiseptic and astringent and in place of tobacco.

• Twigs exude a milky sap if they are crushed.