Twining woody climbing plants, winding anti-clockwise or vines, rarely upright shrubs or small trees, more rarely still herbaceous plants or epiphytes, perennial or deciduous, with simple to uni-serrate hairs.
Alternate spiral leaves, simple, whole, dentate, lobed to palmatifid, frequently peltate, petiolated, petiole frequently pulvinate at both extremes, without stipules, sometimes with spines derived from the petioles, venation, parallelodromous, penninerved or frequently palmatinerved, bifacial, rarely isofacial, in Angelisia and Anamirta with hydathodes derived from trichomes, domatia present in 5 genera as pits or hair tufts. Various types of stomata, frequently cyclocytic.
Rapidly growing stems with trilacunar nodes. Phylloclades are present in Cocculus balfourii.
Dioecious plants, sometimes perfect flowers in Tiliacora acuminata and Parabaena denudata.
Inflorescences in racemiform, paniculate or thyrse with partial inflorescences in a capituliform cyme or pseudo-umbel, multifloral, rarely single or paired flowers, axillary or on sharp branches or cauliflorous trunks, females frequently less branched.
Flowers small, regular to zygomorphic, cyclic to irregularly spiral, hypogynous, basically trimers. Receptacle sometimes with developed gynophore. Sepals 3-12 or more, usually in 2 whorls of 3, rarely 6, free to slightly fused, imbricate or valvate, sometimes less numerous in female flowers. Petals 0-6, in 2 whorls of 3, rarely of 6, free or fused, frequently holding the opposite stamen, sometimes less numerous in female flowers. Androecium of 3-6 stamens free of the perianth, free or fused together in 2-5, fasciculate or monadelphous, introrse, dehiscence along longitudinal, oblique or transversal slits. Female flowers sometimes with staminodes. Gynoecium apocarpous, superior, of 3-6 carpels, usually oppositipetalous, stigma apical, dry, papilous, ovules 2 per carpel, anatropous, hemianatropous to campilotropous, uni- or bitegmic, crassinucellate, the superior epitropous and fertile, the inferior apotropous and abortive, placentation marginal ventral. Male flowers sometimes with carpelodes.
Fruit compound, each unit in a straight or flattened, asymmetric drupe, more or less stipitate, not coalescing, exocarp sub-coriaceous or membranous, mesocarp pulpy, fleshy or fibrous, endocarp woody to petrous, rough, tuberous, echinate or ribbed, often with a recess in the placenta called a condyle.
Seeds slightly curved or spiral, with endosperm absent or present, totally or only ventrally ruminate or not ruminate, oleaginous, embryo straight or curved, with two cotyledons flat or cylindrical, leafy or fleshy, divaricate or applied.
Pollen tricolpate, without operculum nor ribs, tectum perreticulate columellate, endexine granular; or the pollen can be colporate, syncolporate, pororate or hexa-cryptoporate.
Chromosomal number: x = 11, 13, 19, 25. 2n can be up to 52.
Ecology
It is thought that the cauliflorous species are pollinated by small bees, beetles or flies although there are no direct observations of this. Birds disperse the purple or black drupes, for example Sayornis phoebe eats the fruit of Cocculus. In Tinospora cordifolia a lapse of 6–8 weeks has been observed between fertilization and the first zygoticcell division. The menispermaceae predominantly inhabit low altitudetropical forests, where they are climbers, but some genera and species have adapted to arid locations and other temperate climates. C3 photosynthesis has been recorded in Menispermum.
Phytochemistry
The family contains a wide range of benzylisoquinoline compounds and lignans such as furofuran, flavones and flavonols and some proanthocyanidins. The most notable are the wide variety of alkaloids derived from benzyltetrahydroisoquinoline and aporphine, which accumulate as dimers, as well as the alkaloids derived from morphinan and from hasubanan and other diverse types of alkaloid such as derivative of aza-fluoranthene. Sesquiterpenes such as picrotoxin and diterpenes such as clerodane diterpene are also present, while the triterpenes are scarce and where present are similar to oleanane. Ecdysone steroids have also been found. Some species are cyanogenic.
Uses
The Menispermaceae have been used in traditional pharmacopeia and drugs have been formulated from these plants that are of great use in modern medicine. These drugs are based on alkaloids and include tubocurarine from curare, a poison used by indigenous South American tribes on their poison darts, that is obtained from species of Curarea, Chondrodendron, Sciadotenia and Telitoxicum. A similar poison was used in Asia that was obtained from species of Anamirta, Tinospora, Coscinium and Cocculus. Tubocurarine and its synthetic derivatives are used to relax muscles during surgical interventions. The roots of "kalumba" or "colombo" are used in Africa for stomach problems and against dysentery. Species of Tinospora are used in Asia as antipyretics, the fruit of Anamirta cocculus is used to poison fish and birds and the stems of Fibraurea are used to dye fabric yellow. The South East Asian species Coscinium fenestratum, a local Thai remedy for stomach ailments was recently implicated in mass harvesting operations to prepare extracts usable as precursors in the manufacture of the drug MDMA.
Fossils
The extinct genus Callicrypta from the Siberian Middle Cretaceous appears to be referable to Menispermaceae.
Systematic position
The APG II system recognizes this family and places in the order Ranunculales, in the clade eudicots. Their trimerous flower structure is similar to the Lardizabalaceae and Berberidaceae, although they differ from them in other important characteristics. The APW considers that they form part of the Order Ranunculales, and that they are a sister group on the branch formed by the Lardizabalaceae and Berberidaceae families in a reasonably advanced clade of the order. Kinship with the Berberidaceae is further borne out by similarities in phytochemistry e.g. in the presence of berberine and related alkaloids. It is a medium-sized family of 70 genera totaling 420 extant species, mostly of climbing plants. The great majority of the genera are tropical, but with a few reaching temperate climates in eastern North America and eastern Asia.
Taxa included
The genetic factors within this family are very narrow, as there are many genera with one or a few species. There is not currently enough data from genetic studies to evaluate either this situation or the traditional division into five tribes. This division is fundamentally based on characteristics of the seed but there is doubt as to whether the tribes are monophyletic.
