Viscaceae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

s. In past decades, several systems of plant taxonomy recognized this family, notably the 1981 Cronquist system

Cronquist system

The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two...

. In this circumscription, the family includes the several genera of mistletoe

Mistletoe

Mistletoe is the common name for obligate hemi-parasitic plants in several families in the order Santalales. The plants in question grow attached to and within the branches of a tree or shrub.-Mistletoe in the genus Viscum:...

s.

However, the APG II system

APG II system

The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...

, of 2003 (unchanged from the APG system

APG system

The APG system of plant classification is the first, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in 1998 by the Angiosperm Phylogeny Group. It was superseded in 2003 by a revision, the APG II system, and then in 2009 by a further...

, does not recognize the family, treating it as a synonym of Santalaceae

Santalaceae

Santalaceae is a widely distributed family of flowering plants which, like other members of Santalales, are partially parasitic on other plants...

.

Genera once treated as belonging to family Viscaceae include:

• Arceuthobium
  Arceuthobium
  The genus Arceuthobium, commonly called Dwarf Mistletoes, is a genus of 42 species of parasitic plants that parasitize members of Pinaceae and Cupressaceae in North America, Central America, Asia and Africa. Of the 42 species, 39 and 21 are endemic to North America and the United States, respectively...
  
  
• Dendrophthora
• Ginalloa
  Ginalloa
  Ginalloa is a genus of parasitic Mistletoes found in southern and south-eastern Asia. The various species are found in the Andaman Islands and Sri Lanka, the Philippines, Malaysia, the island of Borneo, the island of Java and Papua province in Indonesia, Papua New Guinea, including the Bismarck...
  
  
• Korthalsella
  Korthalsella
  Korthalsella is a genus of flowering plants in the sandalwood family, Santalaceae . It contains about 25 species distributed in Asia, Africa, Australia, and some Pacific Islands.-Selected species:...
  
  
• Notothixos
• Phoradendron
  Phoradendron
  Phoradendron is a genus of mistletoes, native to warm temperate and tropical regions of the Americas. Traditionally, the genus has been placed in the family Viscaceae, but recent genetic research acknowledged by the Angiosperm Phylogeny Group shows this family to be correctly placed within a larger...
  
  
• Viscum
  Viscum
  Viscum is a genus of about 70-100 species of mistletoes, native to temperate and tropical regions of Europe, Africa, Asia and Australasia. Traditionally, the genus has been placed in its own family Viscaceae, but recent genetic research by the Angiosperm Phylogeny Group shows this family to be...