Distribution:  North temperate with Cannabis and one species of Humulus native to the Old World and another species of Humulus a native North American.

Floral structure:

Significant features:  Highly reduced, pentamerous (5-parted), unisexual flowers; species dioecious.  Leaves with a palmate pattern of organization.  A family of minimal floristic significance, but representative of the Order (herbaceous).  However, due to the presence of complex, resin producing glandular trichomes (see possible adaptive significance), the Cannabaceae is of ethnobotanical interest in that both genera are associated with human intoxicants; hops and marijuana and other applications (fiber, oil - Cannabis).  Sometimes included within the Moraceae.
 
 

   Cannabis sativa - staminate inflorescence and flower at anthesis

  Cannabis sativa - pistillate inflorescence and flower at anthesis

  Humulus - overview from Kohler's Medicinal Plants
 

More information on the Cannabaceae