Santalales


The Santalales are an order of flowering plants with a cosmopolitan distribution, but heavily concentrated in tropical and subtropical regions. It derives its name from its type genus Santalum. Mistletoe is the common name for a number of parasitic plants within the order.

Overview

Many of the members of the order are parasitic plants, mostly hemiparasites, able to produce sugars through photosynthesis, but tapping the stems or roots of other plants to obtain water and minerals; some are obligate parasites, have low concentrations of chlorophyll within their shoots, and derive the majority of their sustenance from their hosts' vascular tissues.
Most have seeds without testae, which is unusual for flowering plants.

Classification

The APG III system of 2009 uses this circumscription:
The indicates the Olacaceae are not a good family and should be split. Furthermore, it indicates disagreements about Santalaceae which need to include Viscaceae to be monophyletic. Studies based on DNA sequences also indicate the family Schoepfiaceae should be resurrected to accommodate Schoepfia, Arjona and Quinchamalium.
In the classification system of Dahlgren the Santalales were in the superorder Santaliflorae. The Cronquist system used this circumscription:
The families Viscaceae and Eremolepidaceae are included in the family Santalaceae by the APG. The genera Dipentodon and Medusandra are regarded as unplaced by APG II.
The family Medusandraceae consisted of two genera: Soyauxia and Medusandra. Molecular evidence places them within the family Peridiscaceae of the order Saxifragales. The Chinese monotypic genus Dipentodon is close to Tapiscia and is proposed to constitute the new order Huerteales with Tapisciaceae and the genus Perrottetia formerly placed in the family Celastraceae.