刺榆 ci yu

Planera davidii Hance, J. Bot. 6: 333. 1868; Hemiptelea davidiana Priemer; Zelkova davidiana (Priemer) Bean; Z. davidii (Hance) Hemsley.

Shrubs or trees, to 10 m tall. Bark dark gray to grayish brown. Branchlets grayish brown to brownish purple, pubescent; spines 2-10 cm. Winter buds ovate, usually 3-clustered in leaf axil. Stipules oblong to lanceolate, 3-4 mm. Petiole 3-5 mm, pubescent; leaf blade elliptic, elliptic-oblong, or rarely obovate-elliptic, 4-7 × 1.5-3 cm, base ± cordate to rounded, margin with teeth obtuse, apex acute to obtuse; secondary veins 8-12 on each side of midvein. Fruit asymmetric, yellowish green, ovoid, 5-7 mm, winged only on one side; seed elongate and curved; stalk slender, 2-4 mm. Fl. Apr-May, fr. Sep-Oct. 2n = 56.

Hill slopes, trail sides, planted around houses; below 2000 m. Anhui, Gansu, N Guangxi, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Shaanxi, Shandong, Shanxi, Zhejiang [Korea].

The hard wood is used for utensils, the bark fiber is used for manufacturing staple rayon and sacks, the tender leaves make a good beverage, and oil is extracted from the seeds.