13. Spiraea teretiuscula C. K. Schneider, Bot. Gaz. 63: 399. 1917.
圆枝绣线菊 yuan zhi xiu xian ju
Shrubs to 2 m tall. Branchlets arched, laxly branched, yellowish or purple-yellowish, grooved, puberulous; young branchlets red-brown or brownish, grayish when old, terete; buds small, ovoid, with several scales, pilose. Petiole 1–2 mm, puberulous; leaf blade abaxially gray-green, adaxially greenish, ovate or ovate-elliptic, 6–11 × 4–7 mm, abaxially gray-green, pilose initially, later glabrous, papillose, adaxially greenish, slightly pubescent when young, later glabrous, lateral veins 3 or 4 on each side of midvein, prominent abaxially, base cuneate, margin entire, apex obtuse, sometimes subemarginate. Corymbs compound, 1–3 × 1.5–2.5 cm, up to 25-flowered; rachis and pedicels densely finely pubescent; pedicels 5–9 mm; bracts lanceolate or linear, 2–3 mm, thinly pubescent. Flowers 5–6 mm in diam. Hypanthium turbinate, thinly pubescent abaxially. Sepals broadly triangular, 1–1.5 mm, about as broad as long, apex acute. Petals white, suborbicular, 1.5–2 mm in diam., glabrous, base shortly clawed. Stamens ca. 20, nearly equaling petals. Disk annular, 10-lobed. Carpels sparsely hairy basally; styles terminal, much shorter than stamens.
Mountain forests; 2500--3000 m. S Sichuan.