Skunkbush Sumac

Skunkbush Sumac, courtesy of Intermountain Herbarium

© Intermountain Herbarium, http://herbarium.usu.edu/

Common Name(s):

Skunkbush Sumac
Skunkbrush
Squawbush

Scientific Name:

Rhus trilobata Nutt.

Scientific Name Synonyms:

Rhus aromatica Aiton
Toxicodendron trilobatum (Nutt.) Kuntze

Symbol:

RHTR

Description:

Life Span: Perennial

Origin: Native

Season: Cool

Growth Characteristics: Skunkbrush grows 2 to 8 feet (0.5-2.5 m) in height. Height as well as growth form varies by geographic location: skunkbrush is more branched and compact in the Southwest and taller in the North. The growth form of this thicket-forming shrub may be rounded, mound-like, or upright. Reproduction of skunkbrush is by seed and rhizomes. In many areas, annual growth of skunkbrush begins in April or May.

Flowers of skunkbrush develop early in the spring prior to leaf emergence. Fruit generally ripens from August to October. Drupes mature from June to October. Fruit persists throughout the winter.

Flowers/Inflorescence: Numerous small, yellowish-green to cream-colored flowers are borne on crowded catkin-like clusters near the tips of branches.

Fruits/Seeds: The fruit is a small, red or reddish-orange drupe containing a single nutlet. The fruit is highly acidic.

Leaves: The compound, three-lobed, (sometimes simple), alternate leaves are green above but pale below and are skunky to somewhat sweet-smelling when crushed. Leaflets grow in groups of three and are waxy, and soft-textured. The leaves turn a bright red or orange in the fall.

Stems: Twigs are alternate, brown, pliable, hairy when young, and fragrant when bruised. Older stems have white sapwood, pinkish-red heartwood, and a band of narrow gray-green between the two. Buds are small, yellow, and covered by the persistent leaf stalk bases.

Ecological Adaptations:

Skunkbrush occurs in a variety of habitats including dry rocky slopes, along streams and canyon bottoms, waste places, pastures, roadsides, and on sand dunes, at elevations of 4,500 to 8,000 feet. It is drought resistant; it is intolerant of flooding and high water tables. It typically grows where maximum annual precipitation ranges from 10 to 20 inches. Skunkbrush grows well in sun or partial shade.

Skunkbrush has spreading woody rhizomes and sprouts readily from both the root and crown after disturbance.

Soils: Tolerant of a wide range of soils from nearly bare rock to sand and heavy clay. It grows well on medium to coarsely textured, moist to dry, acidic to slightly alkaline soils. Growth is optimal in fairly deep soil. Skunkbrush grows well on depleted soils.

Associated Species: Nevada bluegrass, cheatgrass, big sagebrush, bluebunch wheatgrass, Idaho fescue, true mountain mahogany.

Uses and Management:

Skunkbrush's forage value is poor for all classes of livestock. Skunkbrush provides some browse for deer, elk, and pronghorn when other more preferred forage is unavailable. In most locations, big game use tends to be heaviest during the winter when food supplies are most limited.

Because the fruit of skunkbrush persists through the fall and winter, this species can provide a ready food source for birds and small mammals when other foods are scarce or unavailable.

Native Americans valued skunkbrush and made use of the fruit, twigs, leaves, and shoots. The fruits were used in foods and medicines, and in the preparation of lemonade-like beverages. Pliable young stems were woven into durable baskets, and the Comanches smoked the leaves. Skunkbrush was also used in making dyes for clothing. Early pioneers ate the salted drupes like popcorn and exudates from the stem as a chewing gum.