Description from Flora of China
Shrubs, woody climbers, or trees to 5 m tall, deciduous. Branchlets and leaflet blades abaxially on midvein usually with prickles. Young branchlets and inflorescence rachises glabrous or rust-colored pubescent. Leaves 3-9(or 11)-foliolate; rachis glabrous or rust-colored pubescent, wings to 6 mm on each side; leaflet blades subsessile, opposite, lanceolate, ovate, or elliptic, 3-12 × 1-3 cm, base attenuate to broadly cuneate, secondary veins 7-15 on each side of midvein and generally faint, margin crenate or entire and often revolute when dry, apex acute to acuminate. Inflorescences terminal on short lateral branchlets and sometimes axillary, 1-7 cm, with less than 30 flowers. Perianth in 2 irregular series or 1 series, with 6-8 ± undifferentiated 0.3-1.5 mm tepals. Male flowers: stamens 4-6; anthers yellow prior to anthesis; connective apex with oil gland; disk pulvinate; rudimentary carpels lacking. Female flowers: carpels 2 or 3, abaxially often with a conspicuous oil gland; styles recurved; staminodes ligulate or lacking. Fruit follicles usually purplish red, 4-5 mm in diam., with a few protruding oil glands. Seeds blackish brown, 3-4 mm in diam. Fl. Apr-May, fr. Aug-Oct. 2n = 66.
Ohba (Fl. Jap. 22c: 37. 2001) treats the plants from Japan and most of China as Zanthoxylum armatum var. subtrifoliolatum (Franchet) Kitamura.
Found in many habitats; below 3100 m. Anhui, Fujian, S Gansu, Guangdong, Guangxi, Guizhou, S Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, S Shanxi, Sichuan, N Taiwan, Xizang, Yunnan, Zhejiang [Bangladesh, Bhutan, India, Indonesia, Japan (including Ryukyu Islands), Kashmir, Korea, Laos, Myanmar, Nepal, Pakistan, Philippines, Thailand, Vietnam].