Plants 30-210 cm; caudices branching, thick, woody. Stems 1-10+, ascending-erect, glabrous, often short fascicles of leaves present at nodes in axes of distal cauline leaves. Leaves: rosettes present at flowering; basal and proximal cauline tapering to elongate, winged petioles, bases nearly sheathing stems, blades linear-lanceolate, 50-260 (including petiole) × 5-45 mm, somewhat fleshy (fresh), margins entire, faces glabrous; mid and distal cauline crowded (robust plants), sessile, blades linear-lanceolate to lanceolate, 20-130 × 5-10(-25) mm, reduced distally, margins entire, apices acute to attenuate, glabrous. Heads 70-320, usually not secund, in thyrsiform-paniculiform arrays, sometimes apically secund, 5-25(-50) × 2-14 cm; branches ascending to arching. Peduncles 2-8 mm, glabrous or sparsely strigose; bracteoles 1-3, distally grading into phyllaries . Involucres campanulate, 2.5-4 mm. Phyllaries in 3-4 series, linear-triangular, unequal, margins involute near tip, sharply acute, the outer ¹ / 3 - ² / 3 length of inner (1-3 × 0.4-0.9 mm), midribs usually enlarged and translucent. Ray florets 8-12; laminae 1-2.5 × 1 mm. Disc florets 10-20; corollas 3-4 mm, lobes 1-1.5 mm. Cypselae (narrowly obconic) 2 mm (5-7 broad ribs lighter than body), sparsely to moderately strigose; pappi 2-3 mm. 2n = 18.

Flowering Jul-Oct. Wet stream banks, springs, marshes; 0-2500 m; Calif.; Mexico (Baja California).

Solidago confinis is similar to S. spectabilis and was treated by A. Cronquist (1994) as a variety of that species.