Rudbeckia missouriensis Engelm. ex Boynton & Beadle

Perennials, to 80 cm (not rhizomatous, not stoloniferous, rosettes at bases of aerial stems). Stems (branches ascending) moderately hirsute (hairs spreading, 1+ mm). Leaves: blades linear to spatulate (not lobed), bases attenuate to cuneate, margins entire or remotely serrulate, apices acute to rounded, faces hirsute; basal petiolate, 5–20 × 0.5–2 cm; cauline petiolate (proximal) or sessile (distal), 2–15 × 0.4–1.5 cm. Heads borne singly or (2–12) in loose, corymbiform arrays. Phyllaries to 1.5 cm (faces hairy, more densely abaxially). Receptacles mostly hemispheric; paleae 5–6.5 mm, apices rounded to acute, abaxial tips glabrous. Ray florets 9–15; laminae elliptic to oblanceolate, 10–25 × 5–8 mm, abaxially sparsely strigose. Discs 8–15 × 10–17 mm. Disc florets 150–250+; corollas proximally greenish yellow, distally purple brown, 4–5.5 mm; style branches ca. 1.5 mm, apices obtuse. Cypselae 1.5–2.7 mm; pappi coroniform, ca. 0.1 mm. 2n = 38.

Rudbeckia fulgida Aiton var. missouriensis (Engelmann ex C. L. Boynton & Beadle) Cronquist