Cannabaceae is a small family of flowering plants. As now circumscribed, the family

5 min readDec 2, 2021

Cannabaceae is a small family of flowering plants. As now circumscribed, the family includes about 170 species grouped in about 11 genera, including Cannabis (hemp, marijuana), Humulus (hops) and Celtis (hackberries). Celtis is by far the largest genus, containing about 100 species.[1]

Cannabaceae is of the rose order (Rosales). Members of the family are erect or climbing plants with petalless flowers and dry, one-seeded fruits. Hemp (Cannabis) and hop (Humulus) are the most economically important species.[3]

Other than a shared evolutionary origin, members of the family have few common characteristics; some are trees (e.g. Celtis), others are herbaceous plants (e.g. Cannabis).

1Description
2Evolutionary history
3Classification
3.1Genera
3.2Phylogeny
4Uses
5References
6External links

Description[edit]

Members of this family can be trees (e.g. Celtis), erect herbs (e.g. Cannabis), or twining herbs (e.g. Humulus).[1]

Leaves are often more or less palmately lobed or palmately compound and always bear stipules. Cystoliths are always present and some members of this family possess laticifers.

Cannabaceae are often dioecious (distinct male and female plants). The flowers are actinomorphic (radially symmetrical) and not showy, as these plants are pollinated by the wind. 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. (A reduced and monophyllous cuplike perigonal bract, properly known as the bracteole, immediately surrounds and protects the seed and is often misnamed as a “calyx”.) Flowers are grouped to form cymes. In the dioecious plants the masculine inflorescences are long and look like panicles, while the feminine are shorter and bear fewer flowers. The pistil is made of two connate carpels, the usually superior ovary is unilocular; there is no fixed number of stamens.

The fruit can be an achene or a drupe.

Evolutionary history[edit]

Cannabaceae likely originated in East Asia during the Late Cretaceous. The oldest known pollen typical of members of Cannabaceae is from the Late Cretaceous (Turonian ~94–90 million years ago) of Sarawak, Borneo. Fossils show Cannabaceae were widely distributed in the Northern Hemisphere during the early Cenozoic, though their distribution shifted towards tropical regions in the later Cenozoic due to changing climates.[4]

Classification[edit]

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. Molecular data from 1990s onwards showed that these families were actually embedded within the order Rosales, so that from the first classification by the Angiosperm Phylogeny Group in 1998, they were placed in an expanded Rosales, forming a group which has been called “urticalean rosids”.[2]

Genera[edit]

Humulus lupulus with nearly mature flowers (hops)

Cannabaceae comprises the following genera:[5][6][7]

Aphananthe Planch. (5 spp.)
Cannabis — Hemp (3 spp.)
Celtis L. (73–109 spp.)
Chaetachme Planch. (1 sp.)
Gironniera Gaudich. (6 spp.)
Humulus L. — Hop (3 spp.)
Lozanella Greenm. (2 spp.)
Parasponia Miq. (5–10 spp.)
Pteroceltis Maxim. (1 sp.)
Trema Lour. (12–42 spp.)

Phylogeny[edit]

Modern molecular phylogenetics suggest the following relationships:[2][8][9][5]

Cladogram of Cannabaceae genera

Moraceae (outgroup)

Cannabaceae

Aphananthe

Gironniera

Lozanella

Cannabis

Humulus

Celtis

Pteroceltis

Chaetachme

Trema (including Parasponia)