Pityopsis ruthii

Perennials, 10-30 cm; rhizomes 3-10 cm. Stems 1-20, erect, green to brown beneath hairs, simple, slender, densely silvery-sericeous, glabrescent. Leaves: basal overwintering, blades linear-lanceolate, shorter than cauline, 30-40 × 3-4 mm, faces sericeous; proximal cauline withering by late summer; cauline crowded, overlapping, spreading to ascending, sessile, blades linear-lanceolate, 30-50 × 2-4.5 mm, margins entire, silvery-sericeous, apices acute, faces silvery-sericeous (hairs anastomosing). Heads 1-8 heads (per branch), in corymbiform arrays. Peduncles 0.5-4 cm, moderately to densely stipitate-glandular, sparsely sericeous; bracteoles 1-3, linear-lanceolate. Involucres narrowly turbino-campanulate, 6-8 mm. Phyllaries in 4-6 series, margins scarious (midnerves pronounced), apices acute, faces sparsely sericeous, moderately to densely stipitate-glandular. Ray florets 9-14(-18); laminae 6-8 mm. Disc florets 30-45; corollas 4.5-6.5 mm, tubes and proximal limbs sparsely pilose, lobes 0.5 mm, glabrous. Cypselae fusiform, ribbed, 3-4 mm, faces sparsely strigose; pappi: outer of linear to linear-triangular scales 0.2-0.8 mm, inner of 25-40 bristles 4.2-6 mm. 2n = 18.

Flowering late summer-fall. Soil-filled cracks of phyllite boulders along rivers, in areas with little shade; of conservation concern; 200-400 m; Tenn.

Pityopsis ruthii is uncommon and known only from the Ocoee and Hiawasee rivers, Polk County. It is federally listed as Endangered and is in the Center for Plant Conservation´s National Collection of Endangered Plants. Changes in river flow due to dams have reduced the size of populations.