Echinacea atrorubens (Nutt.) Nutt.

Plants to 90 cm (roots elongate-turbinate, ± branched). Herbage usually hairy (hairs appressed to ascending, spreading on adaxial leaf faces, to 1.2 mm), rarely glabrous. Stems light green to tan. Basal leaves: petioles 0–12(–20) cm; blades (1-), 3-, or 5-nerved, usually linear or lanceolate, rarely ovate, 5–30 × 0.5–3 cm, bases attenuate, margins usually entire. Peduncles 20–50 cm. Phyllaries linear to lanceolate, 6–15 × 1–3 mm. Receptacles: paleae 9–15 mm, tips red to orange-tipped, usually straight, sharp-pointed. Ray corollas purple, rarely pink or white, laminae reflexed, 19–35 × 2–7 mm, glabrous or sparsely hairy abaxially. Discs ovoid to conic, 25–35 × 20–40 mm. Disc corollas 4.5–5.5 mm, lobes greenish to pink or purple. Cypselae tan, 4–5 mm, faces finely tuberculate, glabrous; pappi to 1.2 mm (major teeth 3–4). 2n = 11.

Rudbeckia atrorubens Nuttall, J. Acad. Nat. Sci. Philadelphia 7: 80. 1834