1. Cotinus obovatus Raf. (American smoke tree, chittam-wood)

C. americanus Nutt.

C. cotinoides (Nutt.) Britton

Rhus americanus (Nutt.) Sudw.

R. cotinoides Nutt.

Pl. 200 e, f; Map 830

Plants shrubs or trees 2–5(–10) m tall, dioecious or nearly so, with yellow wood and aromatic, resinous sap. Twigs at first glaucous, reddish, becoming brown at maturity. Leaves alternate, simple, the petioles 0.5–6.0 cm long. Leaf blades 10–17 cm long, 4–9 cm wide, obovate to elliptic-obovate, entire, with a rounded to bluntly pointed tip, the upper surface glabrous, somewhat glaucous, the lower surface sparsely hairy to nearly glabrous. Inflorescences terminal panicles, to 30 cm long and 15 cm broad, loosely flowered. Flowers mostly sterile and shed early in development, leaving behind elongate stalks 1.0–3.5 cm long, these with spreading purple plumose hairs 1.0–1.2 mm long. Sepals 5, 0.9–1.2 mm long, lanceolate, persistent at fruiting. Petals 5, 1.4–1.6 mm long, oblanceolate, rounded at the tip, yellowish to greenish white. Staminate flowers with the stamens 5, the filaments short, the anthers broadly ovoid. Pistillate flowers with the styles 3, appearing sublateral, unequal, the style of the fertile carpel longer than those of the 2 inconspicuous sterile carpels. Ovary with 1 locule. Fruits 3.5–4.2 mm long, 2.5–3.2 mm wide, asymmetrically ovoid (appearing swollen toward the tip on the side opposite the minute beak), flattened, the outer layer with a network of veins, the fleshy middle layer very thin. Stone more or less kidney-shaped, smooth. 2n=15. May.

Uncommon in the western portion of the Ozark Division (Georgia to Kentucky west to Oklahoma and Texas). Glades and tops of bluffs, usually on calcareous substrates.

American smoke tree is cultivated in the eastern U.S., where it is valued for its interesting smokelike texture of the fruiting panicles and intense yellow to red fall foliage. The long hairs of the sterile pedicels are jointed, spotted with purple, and translucent, which diffuses the light and generates the purple puff-of-smoke effect. The wood yields a clear yellowish orange dye that once was used to color silk and wool, and many of the larger trees were cut down for this purpose.

The Eurasian smoke tree, C. coggygria Scop., also is cultivated in the United States and occasionally has escaped in the northeastern states and Utah. It differs from C. obovatus most visibly in its more oval leaves and even showier inflorescences.