Philadelphus calvescens (Rehder) S. M. Hwang

Shrubs 2-5 m tall. Branchlets of previous year purple, those of current year dark purple, glaucous, glabrous or sparsely hairy. Petiole 5-7(-15) mm; leaf blade ovate or broadly so, 6-15 × 4-7 cm, abaxially glabrous or villous only along veins, adaxially bristly or glabrous, veins 3-5, basifugal, base rounded, margin sparsely serrulate, apex caudate-acuminate, acumen 1-1.5 cm. Racemes 5-9-flowered, sometimes lowest ones 2- or 3-flowered, rarely inflorescences paniculate, 9-15-flowered; rachis purple, glaucous, 5-8 cm; pedicels ca. 1 cm. Calyx tube purple, glaucous, glabrous; lobes ovate, 5-7 × 4-5 mm. Corolla discoid; petals white, broadly obovate or orbicular, 1.5-2 cm, apex retuse or obtuse. Stamens 25-30, longest ones ca. 8 mm; anthers oblong or ovoid, ca. 1.5 mm. Disc and style glabrous. Style ca. 5 mm; stigma clavate, 1.5-2 mm. Capsule obovoid, 7-9 × ca. 5 mm. Seeds ca. 3 mm, shortly tailed. Fl. Jun-Jul, fr. Aug-Oct.

SW Sichuan, NW Yunnan.

* Thickets, valleys; 2400-3500 m.

Philadelphus delavayi L. Henry var. calvescens Rehder, J. Arnold Arbor. 1: 196. 1919; P. calvescens var. compositus S. M. Hwang; P. henryi Koehne var. lissocalyx Handel-Mazzetti.