Viscum

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Viscum

Viscum album growing on a Populus species

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Santalales
Family:	Santalaceae
Genus:	Viscum L.

Species

See text

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 correctly placed within a larger circumscription of the family Santalaceae.

They are woody hemi-parasitic shrubs with branches 15-80 cm long, which grow on other trees. The foliage is dichotomously or verticillately branching, with opposite pairs or whorls of green leaves which perform some photosynthesis (minimal in some species, notably V. nudum), but with the plant drawing its mineral and water needs from the host tree. Different species of Viscum tend to use different host species; most species are able to utilise several different host species.

The flowers are inconspicuous, greenish-yellow, 1-3 mm diameter. The fruit is a berry, white, yellow, orange, or red when mature, containing several seeds embedded in very sticky juice; the seeds are dispersed when birds (notably the Mistle Thrush) eat the fruit, and remove the sticky seeds from the bill by wiping them on tree branches where they can germinate.