Suan Zao Ren

Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H.F.Chow (Rhamnaceae), the wild sour jujube, is a thorny deciduous shrub or small tree of dry hillsides and stony slopes in northern China, typically reaching 1 to 3 meters tall, occasionally more, with zig-zagging, twiggy branches armed with paired stipular spines, one straight and one recurved. The leaves are alternate, ovate to oblong-elliptic, 2 to 5 cm long, with finely serrate margins, three prominent longitudinal veins from the base and a glossy green upper surface. Small, fragrant, greenish-yellow flowers are borne in axillary cymes. The fruit is a small, ovoid to subglobose drupe 1 to 1.5 cm long, ripening dark reddish-brown, with a thin, slightly sour, mealy flesh enclosing a single hard, pointed stone. The flat, brown to reddish, ovate seed kernels extracted from the stones in autumn, slightly oily and about 5 to 8 mm long, constitute Suan Zao Ren in Chinese medicine.