Subshrubs, 6-36 cm (in rock crevices, stems relatively many, erect or pendulous, very leafy); sparsely to densely grayish hairy. Leaves: petioles 2-8(-12) mm; blades pedately 3-lobed (lobes spatulate or linear), or 2-3-pinnatifid (lobes linear-filiform), 4-30 × 4-20 mm, ultimate margins entire. Heads (2-5) in corymbiform arrays, 5-6.5 × 5-6 mm. Peduncles 7-15 mm. Involucres campanulate. Phyllaries 2-16, linear-lanceolate to narrow-ovate, 3.5-5 × 0.5-1.5 mm. Ray florets 8-12; corollas white, laminae broadly oblong or oblong-elliptic to subspatulate, 3-7 × 2-3 mm. Disc florets 30-40; corollas yellow, often purple tinged, tubes 0.8-1 mm, throats tubular, tubular-funnelform, or tubular-campanulate, 1-1.3 mm, lobes 0.3-0.4 mm. Cypselae linear-oblong to narrowly oblanceolate, 1.8-2.5 mm, margins usually prominently calloused, sometimes thin, usually ciliate; pappi of 2(-3+) barbellulate bristles 1.5-2.5 mm plus crowns of hyaline, laciniate scales. 2n = 34.

Flowering spring-fall. Rock and cliff faces; 1000-2600 m; Ariz., N.Mex.; Mexico (Chihuahua).

Perityle coronopifolia is widespread in south-central and southeastern Arizona, and southwestern and south-central New Mexico. The combination of white rays, often pinnatifid leaves, and perennial habit distinguish it.

Duration: Perennial

Nativity: Native

Lifeform: Subshrub

General: Subshrub with many stems from a woody base, 6-36 cm, usually in rock crevices, very leafy, sparsely to densely grayish hairy.

Leaves: On petioles 2-8 mm, blades pedately to ternately lobed, lobes spatulate to linear, or 2-3 pinnatifid, 4-30 mm long by 4-20 mm wide, entire margins.

Flowers: Heads in corymbiform arrays, usually 2-5 flowers, about 6 mm high, on peduncles 7-15 mm; campanulate involucres, phyllaries 2-16, linear-lanceolate to narrow ovate, 3.5-5 mm high and 0.5-1.5 mm wide; ray florets 8-12, white corollas broadly oblong or oblong-elliptic, 3-7 mm long; 30-40 disc florets, corollas yellow, often purple tinged, tubes 0.8-1 mm, throats tubular, tubular-funnelform, or tubular campanulate, 1-1.3 mm, lobes 0.3-0.4 mm.

Fruits: Cypselae linear-oblong to narrowly oblanceolate, 1.8-2.5 mm, margins prominently calloused, sometimes thin, usually ciliate, pappus of 2 barbellulate bristles.

Ecology: Found in rocky crevices and on cliff faces, often on limestone from 4,000-7,500 ft (1219-2286 m); flowers June-October.

Notes: The combination of white rays, often filiform dissected (with large spaces between dissections) and pinnatifid leaves, and perennial habit help to distinguish this species. As does the loosely branched habit.

Ethnobotany: Unknown

Etymology: Perityle comes from Greek peri, around and tyle, a callus, which refers to the thick callused margin of the cypselae, while coronopifolia means having leaves like the genus Coronopus.

Synonyms: None

Editor: SBuckley, 2010