Hydrangea chinensis Maxim.

Hydrangea chinensis is a very common and widespread taxon that forms a species complex out of which a number of segregate species have been recognized. One of the present authors (Bartholomew) feels that species nos. 2-4 below all fall within the pattern of variation found in H. chinensis, in the synonymy of which they would be better treated.

Shrubs 0.5-4 m tall. First and 2nd years' branchlets red-brown to brown, pubescent when young, glabrescent. Petiole 0.5-2 cm, glabrous or pubescent; leaf blade lanceolate, narrowly elliptic, or obovate, 5-12 × 1.5-4 cm, papery to thinly so, both surfaces sparsely pubescent or glabrous except along veins, abaxially usually barbate at vein axils, secondary veins 4-7 on both sides of midvein, abaxially slightly elevated, base cuneate to subacute, margin subentire to roughly serrate, apex caudate-acuminate to acute. Inflorescences umbellate or subcorymbose, 3-7 cm, 10-14 cm wide in fruit, apex flat or slightly arcuate; branches 3 or 5, equal or central one longer and thicker, pubescent. Sterile flowers with sepals 3 or 4, elliptic, obovate, ovate-orbicular, or broadly orbicular, 1.1-3 × 1-3 cm in fruit, margin entire, undulate, or few denticulate. Fertile flowers with calyx tube cupular to campanulate, 0.5-1.5 × 1.5-2 mm; teeth lanceolate to triangular-ovate, 0.5-2 mm. Petals yellow, elliptic to oblanceolate, 2.5-3.5 × 1-1.2 mm, base with a claw ca. 0.5 mm, apex subacute. Stamens 8-11, subequal, 2-4.5 mm; anthers oblong, 0.6-1 mm. Ovary ca. 1/2 or more superior. Styles 3 or 4, erect or slightly spreading, 1-2 mm in fruit; stigmas usually enlarged, decurrent along both sides of style. Capsule fusiform to ovoid-globose, 3.5-5 × 2.4-3.5 mm, projected apical part 1.5-2.5 mm, equaling or slightly longer than calyx tube. Seeds brownish, ellipsoid, ovoid, or subglobose, slightly compressed, 0.5-1 × 0.4-0.5 mm, wingless; seed coat net veined. Fl. Mar-Aug, fr. May-Oct.

Shrubs 0.8-2 m tall. First year's branchlets purplish, brownish when dry. Second year's branchlets usually white, glabrous, without lenticels; bark not peeled off. Petiole 1-2 cm, glabrous; leaf blade abaxially usually purple-red, purplish green when dry, adaxially yellow-green when dry, lanceolate to narrowly so, 8-20 × 1-2.7(-4.5) cm, abaxially sparsely appressed puberulous, adaxially glabrous, secondary veins 7-10 on both sides of midvein, slightly conspicuous on both surfaces, base narrowly cuneate to subacute, margin slightly reflexed, sparsely serrulate, apex obtusely acuminate. Inflorescences corymbose cymes, 5-12 wide, apex truncate to slightly arcuate; peduncle 4-12 cm; branches 3, pubescent. Sterile flowers with sepals 3 or 4, ovate, broadly so, or suborbicular, unequal, 1-1.8 × 0.9-1.5 cm, margin entire or few denticulate. Fertile flowers with calyx tube shallowly cupular, ca. 1 × 2 mm, pilose; teeth lanceolate to ovate-lanceolate, 1.5-2.5 mm. Petals green-white, elliptic to narrowly so, 3-4 × 1-1.5 mm, base with a claw ca. 0.5 mm, apex subacute. Stamens 8-10, subequal, 2.5-3 mm; anthers broadly oblong, 1-1.5 mm. Ovary nearly 1/2 superior. Styles 3 or 4, erect or slightly spreading, 1.5-2 mm in fruit; stigmas capitate, small. Capsule broadly ellipsoid, 2.5-4 mm in diam., projected apical part 2-2.5 mm, slightly longer than calyx tube. Seeds brownish, ovoid-globose to ellipsoid, 0.6-0.8 mm, wingless; seed coat net veined. Fl. May-Jun, fr. Sep-Oct.

Anhui, Fujian, Guangxi, Hunan, Jiangxi, Taiwan, Zhejiang [Japan].

N and W Guangdong, SW Jiangxi.

Sparse to dense forests on mountain slopes, mountain tops, or in valleys; 300-2000 m.

* Dense to sparse forests or thickets in valleys or on mountain slopes; 700-800 m.

Hydrangea angustipetala Hayata; H. angustipetala var. major W. T. Wang & M. X. Nie; H. chloroleuca Diels; H. jiangxiensis W. T. Wang & M. X. Nie; H. macrosepala Hayata; H. obovatifolia Hayata; H. scandens (Linnaeus f.) Seringe subsp chinensis (Maximowicz) E. M. McClintock; H. umbellata Rehder.