Sumacs

Sumacs

Sumacs are a varied group of shrubs and small trees. Yet despite this diversity, most sumacs share a set of similar traits, including pinnately compound leaves, fruit comprised of clustered drupes and small adult size – the largest members of the group reach about 30 feet in height. Many sumacs play important roles in natural ecosystems, while others are popular ornamentals.

Several species have been used as a part of traditional folk medicine for hundreds of years. In fact, modern laboratory techniques have revealed that some sumacs boast antimicrobial properties.

A Fractured Family Tree

Sumacs are part of the cashew family (Anacardiaceae).

The cashew family is an enormous assemblage of plants, comprised of more than 700 different species, including the common mango (Mangiferaindica.), cashew trees (Anacardiumoccidentale), pistachios (Pistacia vera) and poison oak (Toxicodendrondiversilobum), to name a few. The size and complexity of the family have led to frequent changes in the classification of its constituent genera and species. Sumacs provide a great example.

The genus Rhus has contained more than 200 species for much of its history. However, modern botanists have begun reshaping the taxonomy of the group, and most of these species have been moved into other genera. As currently construed, Rhus contains a mere three dozen species.

You can learn more about the systematics of the entire Cashew family here.

Range

At its largest, the genus Rhus contained representatives from most corners of the globe. However, most of the species that remain in the genus are of North American, European or Asian origin. A few species are native to Australia. Africa was home to a number of Rhus species under the historic taxonomic arrangement; but most of these species have been moved, and are now part of the genus Searsia.

Sumacs grow in a wide variety of habitats and ecosystems. Most are early successional species, who quickly move into abandoned fields, vacant lots and fallow farmlands. This tendency – along with their propensity for sprouting additional stems from within existing root systems – often leads sumacs to become troublesome invasive species in some areas. However, in other areas, they are deliberately used in land reclamation projects, to revegetate stripped lands.

Notable Species

Skunkbush Sumac (Rhus trilobata) – Skunkbush, as it is most commonly called, lives throughout the western United States and Canada, including parts of California. Drawing its name from the objectionable odor released from crushed leaves, skunkbush often grows in dense thickets, as other sumacs do.

Fragrant Sumac (Rhus aromatica) – Fragrant sumac is a dense shrub, whose thrice-clustered leaflets superficially resemble those of poison ivy. Most individuals eventually grow to heights of 8 feet or more, but dwarf cultivars are available for smaller spaces. Fragrant sumacs are hardy, drought-resistant plants, capable of thriving on sun-bathed southern exposures.

Smooth Sumac (Rhus glabra) – Smooth sumacs are historically native to the eastern United States, but they have spread into a number of exotic locations, where their root suckering habits have caused them to spread invasively. While this leads many landowners to take steps to eradicate the plant, smooth sumac fruits are important foods for birds and other wildlife.

Staghorn Sumac (Rhus typhina) – Native to the northeastern United States and adjacent portions of Canada, staghorn sumac is widely planted as an ornamental. Several cultivars have been developed, such as the cut leaf form (Rhus typhina ‘Laciniata’). Staghorn sumacs reach about 15 feet in height, but their canopies may spread more than 20 feet. The berries of staghorn sumacs are used in making flavored drinks.

Prairie Flame Leaf Sumac (Rhus lanceolata) – Hailing from the south central United States and parts of Mexico, prairie flame leaf sumacs are also called Texas Sumacs. Like most other sumacs, they produce a short trunk with widely spreading branches. Texas sumacs are among the largest members of the genus, and occasionally reach 30 feet in height.