Cannabaceae
Cannabaceae Martinov is comprises approximately 11 genera and 170–180 species distributed mainly in temperate and tropical regions of the world. Historically, the family was narrowly circumscribed and included only Cannabis and Humulus. However, molecular phylogenetic studies demonstrated that the former family Celtidaceae is nested within Cannabaceae, resulting in a broader circumscription that now includes genera such as Celtis, Trema, Pteroceltis, Aphananthe, and Gironniera. Members are recognized by their simple stipulate leaves, small wind-pollinated flowers, and drupaceous or nut-like fruits.
Key characteristics
- Annual herbs, shrubs, trees, or woody climbers
- Leaves alternate, stipulate, simple or palmately lobed, usually serrate
- Flowers small, greenish, and unisexual
- Plants monoecious or dioecious
- Superior, single-carpellate ovary with one ovule
- Fruit a drupe, drupaceous nutlet, or achene containing a single seed
Distribution
Cannabaceae has a nearly worldwide distribution, occurring throughout temperate, subtropical, and tropical regions. Species of Celtis are widespread in Asia, Africa, Europe, Australia, and the Americas, whereas Cannabis is believed to have originated in Central Asia and is now cultivated or naturalized globally. Members inhabit forests, riverbanks, grasslands, rocky slopes, disturbed habitats, and cultivated lands, demonstrating considerable ecological adaptability. Cannabaceae occurs throughout. Native species of Celtis grow in subtropical forests, riverine woodlands, foothills, and mountainous valleys. Cannabis sativa occurs both as a cultivated and naturalized plant in many parts of the country, particularly in northern Pakistan and temperate valleys. Humulus lupulus has a restricted distribution in cooler mountainous regions and is occasionally cultivated. Species of Trema occur locally in moist subtropical forests.