Annuals (sometimes persisting), 2-60 cm (delicate or robust, stems relatively few to many, erect or spreading); puberulent to hirsute, glandular-pubescent. Leaves: petioles 3-45 mm; blades ovate, cordate, suborbiculate, or triangular, 17-60 × 10-50 mm, margins deeply toothed, lobed, cleft, or divided, lobes indented to irregularly dissected. Heads borne singly or in corymbiform arrays, 4-10 × 4-10 mm. Peduncles 1-70 mm. Involucres campanulate to hemispheric. Phyllaries 10-20, lanceolate or oblanceolate to ovate-lanceolate, 4-6 × 1-2 mm. Ray florets usually 8-14, rarely rudimentary or 0; corollas white, laminae oblong, 1-4(-6) × 1-3 mm. Disc florets 40-100+; corollas yellow, tubes 0.7-1.3 mm, throats tubular to tubular-funnelform, 0.8-1.3 mm, lobes 0.1-0.2 mm. Cypselae suboblong, oblanceolate, or subcuneate, (1.5-)2-3 mm, margins thin (not calloused), long- or short-ciliate; pappi 0 or of 1 antrorsely to retrorsely barbellate bristles 1-3 mm plus crowns of hyaline, laciniate scales. 2n = 65-72 or 100-116.
Flowering year round (depending on latitude). Coastal bluffs, desert plains, slopes, washes; 10-1500 m; Ariz., Calif., Nev., Utah; Mexico; South America (Chile, Peru).
Perityle emoryi is a widespread polyploid of diverse habitats and is often weedy. It is variable; none of the variation appears to have population significance and does not require taxonomic recognition. The range of P. emoryi appears to be gradually expanding.
Duration: Annual
Nativity: Native
Lifeform: Forb/Herb
General: Herbaceous annuals, sometimes persisting, to 60 cm tall, stems delicate to robust, relatively few to many, erect or spreading, herbage puberulent to hirsute and stipitate-glandular.
Leaves: Mostly cauline, often proximally opposite, distally alternate, ovate, cordate, suborbiculate, or triangular, 17-60 mm long and 10-50 mm wide, margins deeply toothed, lobed, cleft, or divided, lobes indented to irregularly dissected, petioles 3-45 mm long.
Flowers: White with yellow centers, radiate, rays (laminae) white, usually 8-14, rarely rudimentary or absent, oblong, 1-6 mm long and 1-3 mm wide, disc florets yellow, 40-100 or more, corolla tubes 0.7-1.3 mm long, throats tubular to tubular-funnelform, 0.8-1.3 mm long, with 4 lobes 0.1-0.2 mm long, involucres campanulate to hemispheric phyllaries 10-20, lanceolate or oblanceolate to ovate-lanceolate, 4-6 mm long and 1-2 mm wide, anther tips triangular, style tips tapered, heads borne singly or in corymbiform arrays, these 4-10 mm long and wide, infloresences on peduncles 1-70 mm long.
Fruits: Cypselae (achenes) suboblong, oblanceolate, or subcuneate, 1.5-3 mm long with thin, uncalloused margins, these long- or short-ciliate, awns solitary or wanting. Pappi absent or of 1 antrorsely to retrorsely barbellate bristles 1-3 mm long plus crowns of h
Ecology: Found on coastal bluffs, desert plains, slopes, and washes, in creosote-bush scrub communities, from 50-5,000 ft (15-1524 m); January-June or flowering year round in favorable conditions.
Distribution: Arizona, California, Nevada, Utah; Mexico; South America (Chile, Peru).
Ethnobotany: Unknown.
Synonyms: Many, see Tropicos
Editor: LCrumbacher2012
Etymology: Perityle comes from the Greek peri, "around," and tyle, "a callus," and meaning "around the margin," referring to the thick calloused margin of the achenes, while emoryi is named after after Maj. William Hemsley Emory (1811-1887), Army officer and Director of the Mexican Boundary Survey.
