7. Perityle emoryi Torrey in W. H. Emory, Not. Milit. Reconn. 142. 1848.
Emory’s rock daisy
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.