Stems striate, terete, glabrous or hairy, often densely puberulent to tomentulose distally, sometimes gland-dotted. Leaves: petioles (5-)10-45 mm; blades (2-)3.5-12(-15) × 1-12 cm. Heads 3-30+, usually tightly clustered. Peduncles 0.5-4 cm. Involucres 4.5-10 × 4-10 mm. Phyllaries 0.5-1 mm wide, apices attenuate. Disc corollas: tubes 1-3.5 mm, throats 2-5.5 mm, lobes 0.5-1 mm. Cypselae 3-5 mm; pappi crowns to ca. 1 mm plus 0-2 bristles 1-4.5 mm. 2n = 36. Flowering spring-fall. Among rocks, boulders, on talus slopes, bluffs, crags, canyons, disturbed roadsides, in volcanic, limestone, and sandstone substrates; 1400-3300 m; Ariz., Calif., Colo., Nev., N.Mex., Okla., Tex.; Mexico (Chihuahua). Populations of Pericome caudata may vary in leaf shape, head size, and indument, particularly in some far western and eastern populations. Central populations (e.g., in Colorado, New Mexico, and Arizona) tend to have relatively large, deltate-hastate leaves with long-attenuate tips and capitulescences of medium-sized heads. Specimens from Nevada and California often have smaller, ovate or cordate distal leaves with short-attenuate tips, as well as larger and fewer heads per capitulescence. Oklahoma specimens are often coarsely pubescent with copious glands and have leaves similar to the Nevada and California populations. This variability does not appear to warrant taxonomic distinction, nor does the presence or absence of pappus bristles appear to be taxonomically significant.
FNA 2006, Kearney and Peebles 1969, Allred and Ivey 2012, Heil et al. 2013
Duration: Perennial Nativity: Native Lifeform: Subshrub General: Aromatic, perennial suffrutescent herbs, up to 1.5 m tall and about as wide; stems widely spreading, striate, glabrous or hairy, the upper stems often densely puberulent, sometimes gland-dotted. Leaves: Usually opposite but occasionally alternate along stems and branches, on petioles 1-5 cm long; blades hastate-triangular, 3-15 cm long, truncate at the base and long-acuminate at the tips. Flowers: Flower heads yellow, discoid, abundant and tightly clustered in cymose panicles; involucres turbinate, 5-8 mm high, the bracts (phyllaries) linear in one equal series, wooly-puberulent, united by their hyaline margins when young and separating with age; florets all discs, the corollas 3-5 mm long, yellow, exceeding the involucre. Fruits: Achenes narrowly oblong, 3-5 mm long, strongly compressed, villous-ciliate; topped with a pappus consisting of a crown of 1 mm ciliate scales and sometimes 1-2 awns. Ecology: Found in rich soils, volcanic, limestone, and sandstone substrates, in coniferous forests, canyons and rocky areas, and on disturbed roadsides, from 6,000-9,000 ft (1829-2743 m); flowers July-October. Distribution: s CO and NM to NV, AZ, and CA; south to MEX. Notes: P. caudata a quite distinctive suffrutescent perennial, and is the only species in the genus found in the U.S. It superficially resembles a yellow-flowered Brickellia, with its dense clusters of narrow discoid flower heads and triangle-shaped, opposite leaves. However, unlike a Brickellia, the seeds of P. caudata have a pappus of scales and awns, not capillary bristles. It could also be compared to the Senecio/Packera group, which has yellow (occasionally discoid) flowers and phyllaries in a single series; however, Senecio and Packera spp. also have a pappus of bristles attached to the seeds. Ethnobotany: Used medicinally to treat fever, cough, flu, toothache, headaches, and to aid in childbirth; also used ceremonially and as a shampoo. Etymology: Pericome is from the Greek peri, around and come, a tuft of hair, alluding to the ciliate margins of the achenes; caudata means with a tail, referring to the long-attenuate leaf apex. Synonyms: None Editor: LCrumbacher 2011, AHazelton 2017