形态描述

落叶灌木，高1-2m，稀达3m。小枝绿色，圆柱形，无毛，常拱垂，嫩枝有稜角。叶互生，三角状卵形或卵圆形，先端长渐尖，基部圆形、截形或微心形，边缘有尖锐重锯齿，两面绿色，上面无毛或有疏柔毛，下面沿脉或脉腋有柔毛；叶柄长5-10mm；托叶膜质，带状披针形，有缘毛，早落。花单生于当年生侧枝顶端，花梗无毛；花直径2.5-6cm；萼片卵状椭圆形，顶端急尖，有小尖头，全缘，无毛，果时宿存；花瓣黄色，宽椭圆形，先端下凹，比萼片长1-4倍。瘦果倒卵形至半球形，褐色或黑褐色，表面无毛，有皱褶。花期4-6月，果期6-8月。

分布地区

见于西湖景区（韬光、桃源岭），生于山坡疏林下的阴湿处，杭州各公园也常见栽培。分布于安徽、福建、甘肃、贵州、河南、湖北、湖南、江苏、江西、陕西、山东、四川、云南、浙江，日本也有。

主要用途

常栽培作园林观赏植物，茎髓可作通草代用品入药。

其它

本种有一重瓣栽培品种：重瓣棣棠花 Kerria japonica‘Pleniflora’——K. japonica (L.) DC. f. pleniflora (Witte) Rehder，花重瓣，我国南北各地普遍栽培，供观赏用。

中国植物志英文版

Rubus japonicus Linnaeus, Mant. Pl. 2: 245. 1771; Corchorus japonicus Thunberg. Shrubs 1–2(–3) m tall. Branchlets green, usually arcuate, terete, angled when young, glabrous. Stipules deciduous after flowering, oblong-lanceolate, membranous, margin ciliate; petiole 5–15 mm, glabrous; leaf blade triangular-ovate or ovate, 3–10 × 2–4 cm, abaxially pilose on veins or in vein axils, adaxially glabrous or sparsely pilose, base subcordate, rounded, or truncate, margin sharply doubly serrate, apex acuminate. Flowers 2.5–6 cm in diam.; pedicel 8–15 mm, glabrous. Sepals persistent in fruit, ovate-elliptic, glabrous, margin serrulate or entire, apex rounded to acute. Petals broadly elliptic, 1.5–2 × 1–1.8 cm, 1–4 × as long as sepals, apex emarginate. Achenes brownish black, obovoid or hemispheric, 4–4.5 × 3.5–4 mm, rugose. Fl. Apr–Jun, fr. Jun–Aug. 2n = 18. Thickets on mountain slopes; 200--3000 m. Anhui, Fujian, Gansu, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, Sichuan, Yunnan, Zhejiang [Japan]. This species is used medicinally and cultivated for ornament.----from “Flora of China”