Description from Flora of China
Cudrania Trécul, nom. cons.; Ioxylon Rafinesque, nom. rej.; Vanieria Loureiro, nom. rej.
Trees, small trees, shrubs, scandent shrubs, or woody vines, evergreen or deciduous, with latex; dioecious. Spines usually present at least on juvenile growth, axillary, straight or curved. Stipules free. Leaves spirally arranged or distichous; leaf blade margin entire, veins pinnate. Inflorescences axillary, globose, spicate, or racemose, without involucral bracts but often with many bracts at base of inflorescence; interfloral bracteoles adnate to calyx, 2-4 around each flower, each with 2 embedded yellow glands. Female inflorescences globose. Flowers free or connate. Male flowers: calyx lobes (3 or)4(or 5), imbricate, free or basally connate, each lobe with 2-7 embedded glands; stamens as many as calyx lobes, erect, straight in bud [or sometimes inflexed]; pistillode present or not. Female flowers: sessile; calyx peltate, fleshy, free or basally connate, apex thick; ovary free or immersed in a receptacle; style short; stigmas 1 or 2, unequal. Syncarp formed by laterally fused flowers and bracts, fleshy, globose or ± globose; calyx and interfloral bracteoles enlarged. Druplets ovoid, surface shell-like, enveloped by a fleshy calyx. Seed thin and fleshy, with endosperm; cotyledons broad, variously twisted, equal or unequal, folded around radicle.
Asian members of this genus have been segregated as Cudrania on the basis of the straight rather than inflexed stamens and shorter style arms, but it has been shown that these characters are unreliable and that Cudrania is best included within Maclura.
The North American tree Maclura pomifera (Rafinesque) C. K. Schneider is cultivated in Hebei.
Cudrania bodinieri H. Léveillé is Capparis cantoniensis Loureiro (Capparaceae).
About 12 species: Africa, Asia, Australia, North America, Pacific Islands, South America; five species in China.