8. Spiraea splendens E. N. Baumann ex K. Koch, Monatsschr. Vereines Beförd. Gartenbaues Königl. Preuss. Staaten. 18: 294. 1875.
Shrubs, 2–10 dm. Stems spreading to ascending, branched. Leaves: petiole 1–4 mm; blade ovate to elliptic, 1–4 × 1–2(–3) cm, chartaceous, base usually obtuse, sometimes acute, margins crenate to serrate distally from middle, venation pinnate craspedodromous, secondary veins prominent, apex usually obtuse, sometimes acute, abaxial surface glabrous or puberulent, adaxial glabrous. Inflorescences mostly terminal, corymbiform or hemispheric panicles, ˂100–1000+-flowered˃, 2–4 × 2–4 cm ˂height 0.8–1 times diam.˃; branches glabrous or puberulent. Pedicels 1–3(–5) mm, glabrous or puberulent. Flowers 2–4 mm diam.; hypanthia hemispheric, 0.5–1.1 mm, abaxial surface glabrous or pubescent, adaxial pubescent; sepals triangular, 0.8–1 mm; petals light to dark pink, ovate to obovate, 1–2.5 mm, ˂veins prominent˃; staminodes 5–10, ˂reduced, fused, appearing as scalloped ring˃; stamens 35–40, 2 times petal length. Follicles oblanceoloid, 2–3 mm, ˂shiny˃, glabrous, ˂adaxial suture sparsely ciliate˃.
Varieties 2 (2 in the flora): w North America.
The name Spiraea densiflora Nuttall ex Rydberg subsp. splendens (E. N. Baumann ex K. Koch) Abrams, which pertains here, is incorrect in relation to the priority of S. splendens (1875) over S. densiflora, which is an illegitimate name with no priority.