Solidago rigida subsp. humilis
Canad. J. Bot. 66: 1805. 1988.
Stems 40–70 (–90) cm, densely (less coarsely) hispid (30–70 hairs/mm2). Leaves: basal (often numerous), small, rarely exceeding 120 × 50 mm; faces densely (less coarsely) hispid (20–60 hairs/mm2); mid to distal lanceolate to ovate. Heads in tightly clumped, usually rounded arrays, 3–13 (–23.5) × (3.5–) 6–13 (–18) cm. Peduncles densely hispido-strigose. Phyllaries: outer densely strigillose; inner often more nearly linear, 0.7–1.2 mm wide, conspicuously strigillose. Disc corolla lobes shallow, 0.9–1.2 (–1.3) mm. Cypselae usually strigillose distally. 2n = 18.
Phenology: Flowering Aug–Oct.
Habitat: Dry to mesic, often sandy or eroded, soils, prairies and open meadows, open grassy clearings in woods
Elevation: 200–1900+ m
Alta., Man., Ont., Sask., Colo., Ill., Ind., Iowa, Kans., Mich., Mo., Mont., Nebr., N.Mex., N.Dak., Okla., S.Dak., Tex., Wis., Wyo.
Subspecies humilis is introduced in Illinois, Indiana, Michigan, and Ontario. The involucres are slightly smaller than those of typical variety.