Shrubs to 100(-200) cm. Leaf blades elliptic to ovate, 10-25(-40+) × 4-15(-20) mm (margins sometimes undulate). Ray florets 0. Disc florets 10-25(-40); corollas 3-4 mm. Cypselae 4-6.5 mm; pappi 2.5-3.5 mm. 2n = 36.

Flowering mostly Sep-Nov. Limestone or alkaline or clay soils, gravelly sites, desert scrub; 800-2000+ m; Ariz., N.Mex., Tex.; Mexico.

Plants of Flourensia cernua usually have a tarry odor and are often locally co-dominant with Larrea tridentata throughout much of the Chihuahuan Desert.

Common Name: American tarwort

Duration: Perennial

Nativity: Native

Lifeform: Shrub

General: Shrub 1-2 m tall, densely leafy.

Leaves: Alternate, blades elliptic to ovate, 10-25 mm by 4-15 mm, pointed, margins sometimes undulate.

Flowers: Heads 1 cm long, nodding, sessile or on short stalks, no ray flowers, disk flowers perfect 10-25, corollas 3-4 mm, yellow; involucre bellshaped, strongly overlapping phyllaries, in 3 series; glutinous herbage, tips spreading, chaffy receptacle.

Fruits: Cypselae flattened, hairy, 4-6.5 mm, pappus of unequal awns, 2.5-3.5 mm, these fringed.

Ecology: Found in desert flats, often co-dominant with creosote from 2,500-6,500 ft (762-1981 m); flowers September-December.

Distribution: se AZ, s NM, sw TX; south to c MEX.

Notes: Often found co-dominant with Larrea tridentata throughout the Chihuahuan desert. Distinguished by being a medium-sized, much-branched shrub with sticky-resinous foliage; oval to elliptic leaves; and small nodding heads with herbaceous pappus, all disk flowers and a pappus of two awns.

Ethnobotany: Used as a treatment for indigestion and other stomach ailments.

Etymology: Flourensia is named for Marie-Jean-Pierre Flourens (1794-1867) a French physiologist, while cernua means drooping or nodding.

Synonyms: None

Editor: SBuckley 2010, FSCoburn 2015