Description from Flora of China
Shrubs erect, 1–3 m tall. Branchlets brownish red to brown, terete, sparsely pubescent initially, finally glabrous; buds small, with 2 scales, glabrous. Petiole 1–2 mm, subglabrous; leaf blade abaxially glaucescent, adaxially dark green, elliptic or elliptic-ovate, 2–2.8 × 1–1.5 cm, abaxially accumbent pilose on veins, adaxially glabrous, lateral veins 4–6 on each side of midvein, slightly raised abaxially, base broadly cuneate, margin ciliate, sharply singly serrate except toward base, apex acute. Corymbs terminal on short, lateral branchlets, compound, 2–3.5 × 3–4 cm, densely numerous flowered; rachis and pedicels accumbent pilose; bracts leaflike, unequal, larger ones 10–15 × 4–6 mm, smaller ones 7–10 × 2–3 mm. Flowers 4–5 mm in diam. Hypanthium campanulate, pilose abaxially. Sepals triangular, 1–1.5 mm, reflexed in fruit, apex mucronate. Petals white, suborbicular, 2–4 mm in diam., glabrous, base shortly clawed. Stamens very unequal, longer ones to 4 mm, exceeding petals, shorter ones nearly equaling petals. Disk annular, irregularly crenulate. Carpels pilose basally; styles somewhat longer than sepals. Follicles erect, divergent, pilose adaxially; styles teminal, mostly straightly spreading. Fl. May–Jun, fr. Sep–Oct.
Lu (Acta Phytotax. Sin. 38: 276. 2000) made the combination Spiraea teniana var. mairei (H. Léveillé) L. T. Lu, based on S. mairei H. Léveillé (Bull. Acad. Int. Géogr. Bot. 25: 43. 1915), described from NE Yunnan (Qiaojia Xian). However, if the two species are indeed conspecific, the name S. mairei has priority over S. teniana.
Moist mixed forests; 2000--2400 m. Yunnan.