Sweet Coneflower

Rudbeckia subtomentosa is often cultivated as an ornamental.

Perennials, to 200 cm (rhizomatous, rhizomes stout). Stems densely hirsute (hairs mostly antrorse, to 0.5 mm). Leaves: blades ovate to elliptic (not lobed), margins denticulate to serrate, apices acute to obtuse or acuminate, faces densely hirsute and gland-dotted (glands fewer adaxially); basal 15–30 × 3–10 cm, bases attenuate; cauline petiolate, ovate to elliptic, proximal 3–25 × 1–15 cm, usually 3–5-lobed, bases truncate to cuneate or rounded. Heads (8–25) in loose, corymbiform to paniculiform arrays. Phyllaries to 1.5 cm (faces hairy and ± gland-dotted). Receptacles conic to hemispheric; paleae 4–6 mm, apices acute, abaxial tips hirsute and gland-dotted. Ray florets 10–16; laminae (yellow to yellow-orange) linear to oblanceolate, 20–40 × 5–8 mm, abaxially sparsely hairy, abundantly gland-dotted. Discs 10–17 × 5–15 mm. Disc florets 200–400+; corollas yellowish green on basal ¹/2, otherwise brown-purple, 3–4.2 mm; style branches ca. 1 mm, apices acute. Cypselae 2–3.5 mm; pappi coroniform, to ca. 0.2 mm. 2n = 38.

Rudbeckia subtomentosa, the sweet coneflower, is a flowering plant in the family Asteraceae and is found in the central United States.