24. Perityle congesta (M. E. Jones) Shinners, Southw. Naturalist. 4: 204. 1959.
Kaibab or Grand Canyon rock daisy
Laphamia congesta M. E. Jones, Proc. Calif. Acad. Sci., ser. 2, 5: 703. 1895
Perennials or subshrubs, 10–30(–45) cm (densely clumped, stems spreading or pendent); hirtellous. Leaves: petioles 2.5–10(–15) mm (shorter than blades); blades elliptic, lanceolate, or ovate, 5–17(–20) × 4–8(–10) mm, (bases cuneate) margins usually entire or with 2(–6) teeth. Heads borne singly or (2–8) in corymbiform arrays, 5–6(–6.5) × 3.5–4.5(–5) mm. Peduncles 3–17 mm. Involucres campanulate. Phyllaries 12–16, narrowly lanceolate, oblong-lanceolate, or lanceolate, 3.2–4.5 × 0.8–1.4 mm. Ray florets 0. Disc florets 30–40; corollas yellow, tubes 0.8–1 mm, throats tubular to subfunnelform, 1.2–1.5 mm, lobes 0.3–0.5 mm. Cypselae narrowly oblanceolate, (2–)2.5–3 mm,margins thin-calloused, short-hairy; pappi of 1–2 subequal or unequal bristles 2–2.7 mm. 2n = 32.
Flowering spring–fall. Crevices of limestone cliffs and bluffs; of conservation concern; 900–2700 m; Ariz.
The leaf blades of Perityle congesta usually have a tooth on each margin, cuneate bases, and unobtrusive veins abaxially; those of P. tenella usually have serrate margins, truncate bases, and raised veins abaxially. Perityle congesta is found on both rims and extending into the Grand Canyon and northward almost to the Utah border. Available specimens suggest that P. congesta and P. tenella intergrade where their ranges overlap in northwestern Arizona on the Colorado Plateau. Specimens from the Colorado Plateau have intermediate leaf shapes and induments.