72b. Solidago rigida Linnaeus subsp. humilis (Porter) S. B. Heard & Semple, Canad. J. Bot. 66: 1805. 1988.
Solidago rigida var. humilis Porter in T. C. Porter and J. M. Coulter, Syn. Fl. Colorado, 63. 1874; Oligoneuron bombycinum Lunell; O. canescens Rydberg; Oligoneuron rigidum (Linnaeus) Small var. humilis (Porter) G. L. Nesom; S. bombycinum (Lunell) Friesner; S. canescens (Rydberg) Friesner; S. jacksonii (Kuntze) Fernald var. humilis (Porter) Beaudry; S. parvirigida Beaudry; S. rigida var. canescens (Rydberg) Breitung
Stems 40–70(–90) cm, densely (less coarsely) hispid (30–70 hairs/mm 2 ). Leaves: basal (often numerous), small, rarely exceeding 120 × 50 mm; faces densely (less coarsely) hispid (20–60 hairs/mm 2 ); 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.
Flowering Aug–Oct. Dry to mesic, often sandy or eroded, soils, prairies and open meadows, open grassy clearings in woods; 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.
