Description from Flora of China
Bocconia cordata Willdenow, Sp. Pl. 2: 841. 1797; Macleaya cordata var. yedoensis (André) Fedde; M. yedoensis André.
Herbs, erect, basally lignified, yellow lactiferous. Stems green, glaucous, 1-4 m, smooth, branched above in inflorescence. Leaves: petiole 1-12 cm, adaxially shallowly channeled; blade glaucous abaxially, gray-green adaxially, broadly ovate or suborbicular, 5-27 × 5-25 cm, usually 7- or 9-parted or lobed, apex acute, acuminate, obtuse, or rounded; lobes semicircular, quadrate, deltoid, or orbicular, margin undulate, incised, or serrate to serrulate, abaxially sparsely villous, adaxially glabrous, basal veins usually 5, lateral veins 2 pairs, rarely 3, veinlets netted. Panicles large, terminal and axillary, multiflorous, 15-40 cm; bracts narrowly lanceolate. Pedicel 2-7 mm. Flower buds almost white, clavate, ca. 10 mm. Sepals yellowish white, obovate-oblong, cymbiform, ca. 10 mm. Stamens 24-30; filaments ca. 5 mm; anthers linear, ca. equal to filaments. Ovary obovoid to narrowly obovoid, 2-4 mm, base attenuate, apex rounded; styles ca. 1 mm; stigmas 2-lobed, decurrent to styles. Capsule narrowly obovoid or oblanceolate, 1.3-3 cm × 5-7 mm, glabrous, base attenuate, apex rounded or obtuse. Seeds 4-6(-8), ovoid, 1.5-2 mm, attached bilaterally, sessile, seed coat with regular alveolate foveolae, narrowly carunculate. Fl. and fr. Jun-Nov. 2n = 10, 20*.
Foothills, forests, among shrubs or tussocks on low mountains, riversides, pool sides; 100-800 m. Anhui, S Gansu, Guangdong, Guizhou, Henan, Hubei, Hunan, Jiangxi, Shaanxi, Shanxi, Sichuan, Taiwan, Zhejiang [Japan].