Description :

• Shrubby (rarely minute herbs), monoecious or dioecious, brittle, glabrous, hemiparasitic aerial parasites on dicotyledons (rarely gymnosperms); branching usually dense and intricate, forked or whorled; internodes rounded or compressed, sometimes ribbed and twisted 90º; nodes often swollen, articulated
• Leaves opposite, simple, entire, sometimes reduced to scales; stipules 0
• Inflorescence a typical or modified dichasium subtended by a pair of usually fused bracts (bracteal cup)
• Flowers unisexual, minute (± 2 mm across), solitary or clustered with 3 or 4, free, valvate, often much-reduced perianth segments
• Monoecious plants with central flower of dichasium usually male and lateral ones female, or occasionally with all flowers male or female
• Dioecious plants with male dichasia usually bearing 3(2) flowers; female dichasia with a solitary flower in the bracteal cup
• Male flowers : stamens opposite to and as many as perianth segments, episepalous or free; anthers dehiscing by numerous pores; pollen spherical, spined or smooth; style vestigial or lacking
• Female flowers : ovary inferior, 1-locular; ovules undifferentiated, with 2 embryo sacs originating on a short placental column; style simple; stigma linear or capitate
• Fruit a 1-seeded berry with a viscous layer inside the vascular bundles, white, yellow, orange, or red, smooth or warty, pedicelled or sessile in the bracteal cup; perianth segments occasionally persistent; style usually persistent
• x = 10, 11, 12 (polyploidy)

Nomenclature:

• Viscum L.
  • Linnaeus: 1023 (1753)
  • Linnaeus: 448 (1754)
  • Harvey: 578 (1862)
  • Sprague: 393 (1910)
  • Sprague: 121 (1915)
  • Balle: 11 (1969)
  • Wiens & Tölken: 43 (1979)
  • Polhill & Wiens: 279 (1998)

Distribution & Notes:

• Global : Species ± 100, widely distributed in the African (including Madagascan) and Asian tropics with extensions into north temperate zones of Europe and Asia
• Southern Africa : Species 17 (the only occurrence of the genus in south temperate regions), throughout the region