As an adaptation to this kind of pollination, the calyx and corolla are radically reduced to only vestigial remnants found as an adherent perianth coating the seed.

Classification systems developed prior to the 1990s, such as those of Cronquist (1981) and Dahlgren (1989), typically recognized the order Urticales, which included the families Cannabaceae, Cecropiaceae, Celtidaceae, Moraceae, Ulmaceae and Urticaceae, as then circumscribed.

[8] Modern molecular phylogenetics suggest the following relationships:[3][9][10][5] Moraceae (outgroup) Aphananthe Gironniera Lozanella Cannabis Humulus Celtis Pteroceltis Chaetachme Trema (including Parasponia) Carbon dating has revealed that these plants may have been used for ritual/medicinal purposes in Xinjiang, China as early as 494 B.C.

[12] Some plants in the genus Cannabis are cultivated as hemp for the production of fiber, as a source of cheap oil, for their nutritious seeds, or their edible leaves.

Induced parthenocarpy in pistilate flowers, and selective breeding are used to produce either higher or lower yields of tetrahydrocannabinol (THC), other cannabinoids, as well as terpenes with desired flavors or aromas, such as blueberry, strawberry, or even citrus.

Many trees in the genus Celtis are grown for landscaping and ornamental purposes, and the bark of Pteroceltis is used to produce high-end Chinese rice paper.