Annuals, biennials, or perennials, to 100 cm (taprooted or roots fibrous).
Stems hispid to hirsute (hairs spreading, 1+ mm).
Leaves: blades elliptic, lanceolate, or ovate (not lobed), bases attenuate to cuneate, margins entire or serrate, apices acute, faces hispid to hirsute; basal petiolate, blades 8-30 × 0.5-7 cm; cauline petiolate or sessile, blades (sometimes pandurate) 3-20 × 0.4-4 cm.
Heads borne singly or (2-5) in loose, corymbiform arrays.
Phyllaries to 3 cm (faces hispid to hirsute).
Receptacles hemispheric to ovoid; paleae 4-6 mm, apices acute, often attenuate, abaxial tips hirsute to hispid.
Ray florets 8-16; laminae (usually uniformly yellow to yellow-orange or with a basal maroon splotch, sometimes mostly maroon) elliptic to oblong or oblanceolate, 15-45 × 5-10 mm, abaxially hispid to hirsute.
Discs 12-22 × 10-20 mm.
Disc florets 250-500+; corollas proximally yellowish green, distally brown-purple, 3-4.2 mm; style branches ca. 1.5 mm, apices subulate.
Cypselae 1.5-2.7 mm;
pappi 0. Some strains of
Rudbeckia hirta are cultivated and/or used in seed mixes for 're-naturalization' and erosion control.