37. Spiraea x vanhouttei (Briot) Carrière, Rev. Hort. 48: 260. 1876.
菱叶绣线菊 ling ye xiu xian ju
Spiraea aquilegiifolia Pallas var. vanhouttei Briot, Rev. Hort. 37: 269. 1866.
Shrubs to 2 m tall. Branchlets arching, red-brown, turning gray-brown to black-brown when old, glabrous; buds ovoid, small, with several scales, glabrous, apex obtuse. Petiole 3–5 mm, glabrous; leaf blade bluish gray abaxially, dark green adaxially, rhombic-ovate, 1.5–3.5 × 0.9–1.8 cm, glabrous on both surfaces, inconspicuously 3-veined or pinnately veined, base cuneate, margin usually 3–5-lobed, incised doubly serrate, apex acute. Umbels pedunculate, 2.5–4 cm, many flowered, leafy at base; pedicels 7–12 mm, glabrous; bracts linear, 2–5 mm, glabrous. Hypanthium campanulate, glabrous abaxially. Sepals triangular or ovate-triangular, erect in fruit. Petals white, suborbicular, 3–4 mm, base shortly clawed, apex obtuse. Stamens 20–22, much shorter than petals, some abortive. Disk annular, unevenly lobed. Carpels glabrous; styles shorter than stamens. Follicles slightly spreading; styles suberect. Fl. May–Jun, fr. Aug–Sep.
Cultivated. Guangdong, Guangxi, Jiangsu, Jiangxi, Shaanxi, Shandong, Sichuan [of cultivated, hybrid origin].
This taxon is a hybrid between S. cantoniensis and S. trilobata.