Plant of the Month: November, 2000

by Russell Stevens

Smooth Sumac
Rhus glabra

Characteristics: Smooth sumac is a deciduous native perennial shrub reaching 10 feet. Sometimes, individual plants form a small tree reaching 20 feet. Smooth sumac can be found in bottom land or upland, and although it grows best on sandy soils, it can grow on a variety of soil types. Leaves are pinnately compound, which means leaflets are attached in two rows along an axis, with eleven to thirty-one paired leaflets, except at the end (incidentally, some unrelated species have leaves whose axes branch or fork, in which case the leaf is called bipinnately compound). Leaflets are almost stalkless–meaning almost without a petiole–2 to 4 inches long, narrowly lance-shaped, rounded at the base, and saw-toothed at the margins. Leaflets are shiny green above and paler beneath, turning reddish in autumn. The bark is gray and smooth. Fruits are single-seeded drupes, which means they have a pulpy interior over a hard inner shell that encloses the seed. The fruits are somewhat flattened, have short red velvety hairs, and form dense panicles (clusters) at the end of branches. They mature in late summer and may remain on the shrub into the winter. Smooth sumac forms thickets from root sprouts.

Area of Importance: All except far western portions of Oklahoma and Texas.

Attributes: Smooth sumac and other plants in the Rhus genus are important to white-tailed deer for year-round use. Quail, turkey, and many other species of birds eat the seed. A dense clump of smooth sumac provides cover for quail and other wildlife. Goats prefer to browse it, and cattle sometimes do. Smooth sumac can be grown as an ornamental and has sour fruits that can be crushed and made into a drink like lemonade. Smooth sumac contains tannic acid, and extracts were used to tan leather. Sumac is a common name derived from shoe-make, referring to its use in tanning.

Problems: Smooth sumac often increases on poorly managed rangeland, creating a brush problem. Controlling it with fire is difficult because burning often encourages its spread.

I.D. Tip: Look for a shrub forming a thicket that is somewhat open underneath and has large shiny green leaves made up of eleven to thirty-one leaflets. The dense clusters of seed are red and showy in the fall. The leaf axis is not winged.

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Hundreds of plants are identified in the Noble Foundation Plant Image Gallery.