The World Flora Online

SELECTED REFERENCES

Miller, N. G. 1970. The genera of the Cannabaceae in the southeastern United States. J. Arnold Arbor. 51: l85-203.

Herbs , annual or perennial, taprooted or rhizomatous, erect or twining, aromatic, pubescent with small glands and hairs, hairs with or without cystoliths (structures within cells with basal calcium carbonate concretions or crystals). Stems usually branched, usually ridged or furrowed. Leaves decussate proximally, often alternate distally, simple to palmately lobed or compound, petiolate; stipules persistent, triangular. Leaf blade: margins serrate. Inflorescences axillary or terminal, bracteate; staminate inflorescences compound cymes or panicles, loose, erect or somewhat pendent; pistillate inflorescences spikes, pseudospikes, or racemes. Flowers unisexual, staminate and pistillate usually on different plants, when on same plants (in some populations and cultivars), then staminate flowers produced before pistillate flowers, transitional-bisexual flowers sometimes occurring. Staminate flowers 20-200+, pedicellate; sepals 5, hypogynous, greenish or whitish; stamens 5, hypogynous, opposite sepals; anthers dehiscing longitudinally and basipetally. Pistillate flowers 10-50, often paired, pairs often interpreted as cymes, subsessile, tightly covered or loosely subtended by bract or bracteole; perianth a thin undivided layer adhering to ovary, obscure; pistil 1, usually 2-carpellate; ovary superior, 1-locular; ovule 1 per locule; style short, apical; stigma 2-branched, long, filiform. Fruits achenes, crustaceous, covered loosely or tightly by persistent, accrescent perianth. Seeds fleshy; endosperm little; embryo curved or coiled.

Herbes dressées ou rampantes. Feuilles alternes ou opposées, simples ou entières ou ± palmées-lobées; stipules présentes. Inflorescences ♂ en panicules axillaires; inflorescences ♀ formées de fleurs sessiles fasciculées ou réunies en strobiles. Bractées longues et persistantes. Fleurs ♂ pentamères. Calice à sépales imbriqués; corolle absente. Étamines 5, alternisépales. Fleurs ♀ à calice entourant l'ovaire entier. Ovaire sessile, uniloculaire, uniovulé; ovule pendant. Achaine ou capsule entourée par le calice persistant . Graine sans endosperme. Embryon spiralé ou courbe.

Herbes'dioïques, dressées ou grimpantes, aromatiques et sans latex.'Feuilles'alternes (rarement opposées), pétiolées, palminerves, à stipules latérales.'Inflorescences'en cymes axillaires, les ♀ plus condensées que les ♂.'Fleurs'petites, verdâtres, les ♂ à 5 étamines opposées aux segments du périgone, à filet non recourbé dans le bouton; les ♀ à périgone cupuliforme entourant l'ovaire 1-loculaire, 1-ovulé, surmonté de 2 longs stigmates filiformes.'Fruit : un akène.\n\t\t\tDeux genres :'Humulus L. avec 2 espèces (dont le Houblon) et Cannabis L. avec 1 espèce, le Chanvre, cultivée au Congo belge.

Inflorescences numerous and axillary, flowers dioecious and wind-pollinated Male inflorescences paniculate, flowers with perianth uniseriate, 5-lobed, imbricate; stamens 5, opposite the perianth lobes, anthers straight, erect in bud, 2-thecous, dehiscing at first by apical pores but soon also lengthwise; pistillode absent Female inflorescences strobilate, flowers ± sessile, crowded, tightly enclosed or loosely subtended by small or large persistent bracteoles; bracts present; perianth membranaceous, entire, investing the ovary; ovary superior, sessile, 1-locular; ovule 1, pendulous, anatropous; style terminal, short; stigmas 2, long filiform Fruit an achene covered by the persistent perianth; endosperm sparse, fleshy and oily; embryo curved or spirally coiled Herbs, annual or perennial, erect or climbing, without latex Leaves alternate or opposite, petiolate, simple and undivided to palmately lobed or digitately compound; stipules free or fused Male inflorescences paniculate, flowers with perianth uniseriate, 5-lobed, imbricate; stamens 5, opposite the perianth lobes, anthers straight, erect in bud, 2-thecous, dehiscing at first by apical pores but soon also lengthwise; pistillode absent Female inflorescences strobilate, flowers ± sessile, crowded, tightly enclosed or loosely subtended by small or large persistent bracteoles; bracts present; perianth membranaceous, entire, investing the ovary; ovary superior, sessile, 1-locular; ovule 1, pendulous, anatropous; style terminal, short; stigmas 2, long filiform Fruit an achene covered by the persistent perianth; endosperm sparse, fleshy and oily; embryo curved or spirally coiled Herbs, annual or perennial, erect or climbing, without latex Leaves alternate or opposite, petiolate, simple and undivided to palmately lobed or digitately compound; stipules free or fused

Fls unisexual, small and inconspicuous, the male with 5 erect stamens on short or very short filaments opposite the 5 sep, the female with a short, ± entire, membranous cal enclosing the ovary, or the cal often much reduced in Cannabis; pet none; ovary unilocular, with a single pendulous, anatropous ovule; style short, with 2 elongate, filiform stigmas; fr a small nut or an achene, in Humulus invested by the persistent cal; seeds with curved or coiled, dicotyledonous embryo and scanty endosperm; erect or twining herbs without milky juice; lvs opposite at least below, palmately lobed or compound (except sometimes the upper); infls axillary to the upper (often reduced) lvs, the male relatively loose, branched, and many-fld, the female more compact and few-fld. 2/4.

Herbs, annual or perennial, erect or twining, dioecious or sometimes monoecious, often with cystoliths (a hard calcium carbonate structure at base of a hair). Stems furrowed or winged. Stipules free. Leaves alternate or opposite, palmately lobed or compound, sometimes simple. Male inflorescences a bracteate cymose panicle. Male flowers: pedicellate; sepals 5, free; petals absent; stamens 5, opposite sepals; filaments short; anthers 2-loculed, dehiscent by longitudinal slits. Female inflorescences a bracteate spicate cyme much reduced in Cannabis, pendent or erect. Female flowers: sessile; calyx appressed to ovary, membranous; petals absent; ovary 1-loculed; ovule solitary, pendulous from locule apex; style 2-parted, branches filiform. Fruit an achene, covered by persistent calyx; endosperm fleshy; embryo curved or spirally involute.

Male paniculate; perianth 5-partite with imbricate segments; stamens 5, opposite the tepals, the anthers straight, erect in bud, 2-thecous, at first dehiscing by apical oval pores but soon dehiscing lengthwise; vestigial ovary absent Flowers mostly dioecious, axillary, wind-pollinated Fruit an achene covered by the persistent perianth; endosperm sparse, fleshy and oily; embryo curved or spirally coiled Female ± sessile, crowded or strobilate, tightly covered or loosely subtended by small or large conspicuous persistent bracteoles; bracts also present; perianth membranous, entire, investing the ovary; ovary superior, sessile, 1-locular with 1 pendulous anatropous ovule; style terminal, short, with 2 long filiform stigmas Annual or perennial erect or climbing herbs without latex Leaves alternate or opposite, simple, undivided or palmately lobed or divided into separate leaflets; petioles well developed; stipules present, free or fused Flowers mostly dioecious, axillary, wind-pollinated Fruit an achene covered by the persistent perianth; endosperm sparse, fleshy and oily; embryo curved or spirally coiled Female ± sessile, crowded or strobilate, tightly covered or loosely subtended by small or large conspicuous persistent bracteoles; bracts also present; perianth membranous, entire, investing the ovary; ovary superior, sessile, 1-locular with 1 pendulous anatropous ovule; style terminal, short, with 2 long filiform stigmas Annual or perennial erect or climbing herbs without latex Leaves alternate or opposite, simple, undivided or palmately lobed or divided into separate leaflets; petioles well developed; stipules present, free or fused

A family of only 2 genera occurring naturally in the temperate parts of the northern hemisphere, formerly included in either Urticaceae or >i>Moraceae. The number of species is in dispute; >i>Cannabis is usually considered to be monotypic but a second species >i>C. ruderalis Janisch has been described; >i>Humulus is usually considered to contain 2 species although 3–4 have been claimed. Although small the family is of considerable economic importance, >i>Humulus being used to flavour beer and >i>Cannabis to produce the fibre hemp and the drug variously known as bhang, dagga, hashish, pot, marijuana and Indian hemp. A very full account of the family and generic characteristics, together with an extensive bibliography, is given by N. G. Miller (Journ. Arn. Arb. 51: 185–203 (1970))