Description:

• Erect, tall, annual, aromatic herbs without latex, dioecious, rarely monoecious; most parts of plant with minute adpressed swollen-based glandular hairs
• Male and female plants dimorphic:
  • males taller and more slender with longer narrower leaflets, inflorescence sparsely leafy, plant dying soon after flowering
  • female shorter, more robust, inflorescence densely leafy, plant living several months after pollination
• Leaves alternate (opposite at stem base), petiolate, palmately compound or lobed, leaflets uneven in size, serrate; stipules lateral, linear, acute, persistent
• Male inflorescences axillary, much-branched, lax, cymose panicles, bristly-hairy, exceeding leaves but bearing few scattered leaves
• Male flowers small, pedicellate, regular; perianth uniseriate, lobes 5, free, imbricate, greenish or whitish, boat-shaped, spreading or reflexed; stamens 5, opposite perianth lobes, erect in bud, pendulous at maturity, dehiscence longitudinal, basipetal; filaments short; pistillode 0
• Female inflorescences axillary, short, compact, not exceeding leaves, few-flowered
• Female flowers in pairs, each with stipule-like bract and small green organ ('bracteole' or 'calyx') completely enveloping ovary and loosely enclosing mature fruit, forming basally swollen tubular sheath acuminate at apex and covered with fine hairs and short-stalked or sessile resinous glands; perianth thin, undivided, tightly enveloping ovary and mature fruit (often reduced or absent in cultivated forms), marbled with light and dark areas; ovary superior, sessile, ± globose, 1-locular; ovule solitary, anatropous, bitegmic, crassinucellar and pendent from near apex of locule; style short; stigma branches 2, long, filiform, densely pubescent, caducous
• Fruit a globular to ovoid achene tightly covered by thin crustaceous perianth, reticulate venation of surface beneath perianth visible
• Seed 1; endosperm sparse, fleshy, oily; embryo strongly curved or coiled; cotyledons fleshy
• x = 10 (polyploidy)

Classification Notes: Due to its long association with man the genus shows considerable variation in growth form, achene size, and chemical content. This variation has led to various taxonomic interpretations. Emboden (1974) and Schultes et al. (1974) adduce good reasons for distinguishing three species. Small & Cronquist (1976) interpret Cannabis as a variable monotypic (*C. sativa L.) genus with 4 infraspecific taxa. Anderson (1980) considers Cannabis as comprising 3 species. Wilmot-Dear (1991) considers Cannabis as comprising 1 very variable species with 3 infraspecific taxa.

Nomenclature:

• *Cannabaceae
  • Endlicher: 286 (1837)
  • Candolle: 30 (1869)
  • Bentham: 356 (1880)
  • Engler: 96 (1888)
  • Rendle: 16 (1916)
  • Wilmot-Dear: 10 (1991)
  • Kubitzki: 204 (1993)

Distribution & Notes:

• Global: Genera 2, native to temperate parts of the northern hemisphere, Eurasia to SE Asia and North America
• Southern Africa: Genus 1 with 1 species naturalised in Africa

References:

• ANDERSON, L.C. 1980. Leaf variation among Cannabis species from a controlled garden. Botanical Museum Leaflets Harvard University 28
• BENTHAM, G. 1880. Urticaceae. Tribus Cannabineae. In G. Bentham & J.D. Hooker, Genera plantarum 3,1. Lovell Reeve & Co., London
• CANDOLLE, A. DE. 1869. Cannabineae. In A. de Candolle, Prodromus 16,1. Masson & Sons, Paris
• EMBODEN, W.A. 1974. Cannabis - a polytypic genus. Economic Botany 28
• ENDLICHER, S.L. 1837. Cannabineae. Genera plantarum secundum ordines naturales disposita 1. Beck, Vienna
• ENGLER, A. 1888. Moraceae. Subfamily Cannaboideae. Die natürlichen Pflanzenfamilien III,1
• KUBITZKI, K. 1993. Cannabaceae. In K. Kubitzki, J.G. Rohwer & V. Bittrich, The families and genera of vascular plants - dicotyledons 2. Springer-Verlag, Berlin
• RENDLE, A.B. 1916. Cannabinaceae. Flora of tropical Africa 6,2
• SCHULTES, R.E., KLEIN, W.M., PLOWMAN, T. & LOCKWOOD, T.E. 1974. An example of taxonomic neglect. Botanical Museum Leaflets Harvard University 23
• SMALL, E. & CRONQUIST, A. 1976. A practical and natural taxonomy for Cannabis. Taxon 25
• WILMOT-DEAR, C.M. 1991. Cannabaceae. Flora zambesiaca 9,6

Resources:

• Cannabaceae genus: *Cannabis