Chaetopappa hersheyi

Perennials, 1-2(-5) cm, eglandular; taprooted, forming mats from systems of rhizomelike caudex branches. Leaves even-sized, densely overlapping; blades linear to oblanceolate, 3-8 × 0.5-1 mm, coriaceous, bases not clasping (margins ciliate, midnerves strongly raised, longitudinally 2-grooved adaxially), apices spinulose, faces glabrous. Involucres cylindro-turbinate, 4.5-5 × 2.5-4 mm. Ray florets 6-10; corollas white. Disc florets 5-6, bisexual. Cypselae ca. 1.5 mm, 2-3- (ray) or 5- (disc) nerved, strigose; pappi in 2 series, outer of minute scales less than 0.1 mm plus inner of (4-)5(-6) bristles 2-4.2 mm. 2n = 16.

Flowering May-Aug. Walls, ledges, and banks, limestone canyons; 1500-2400 m; N.Mex., Tex.