Perennials, 6-35+ cm. Caudices ± branched, branches notably thickened distally. Stems 1-10, erect, unbranched. Leaves all basal, new leaves tightly clustered; blades spatulate or oblanceolate to linear-oblanceolate, entire, glabrous or sparsely to rarely moderately hairy, moderately to densely gland-dotted. Heads 1-10 per plant, borne singly. Peduncles 5-35 cm, ± hairy proximally, densely hairy distally. Involucres 10-15 × 12-20 mm. Outer phyllaries 8-12, 5-7.5 mm, margins 0-0.2 mm wide, sometimes slightly scarious, abaxial faces ± hairy. Ray florets 14-27; corollas 11.8-20 mm. Disc florets 50-100+; corollas yellow, 3.4-4 mm. Cypselae 2.4-3.4 mm; pappi of 4-7 obovate, usually non-aristate scales 1.9-2.2 mm. 2n = 28.
Flowering (Apr-)May-Jun(-Oct). Alvars (limestone flats), openings in woods; 200 m; Ont.; Ill., Ohio.
Tetraneuris herbacea is in the Center for Plant Conservation´s National Collection of Endangered Plants.