The order Santalales, with its approximately 160 genera and 2,200 species distributed worldwide, is a monophyletic group that has long occupied an unresolved position at the base of the Gunneridae. Recently, phylogenetic studies based on molecular data from the complete chloroplast genome indicate a position of Santalales at the base of the Asterids.Moore M., Bell C., Soltis P. S., Soltis D. E.. 2008. Analysis of an 83-gene, 86-taxon plastid genome data set resolves relationships among several deep-level eudicot lineages. From Botany 2008: Botany without Borders, annual meeting of the Botanical Society of America, Vancouver, British Columbia, Canada, 97. Santalales is ecologically diverse and includes free-living plants, such as Erythropalum, as well as (hemi)parasites. Among the latter are species that parasitize stems or shoots, such as the mistletoes of the genus Misodendrum, and root parasites, including the well-known and economically important sandalwood tree (Santalum album), whose aromatic wood is a component of many perfumes. The APG III classification system recognized seven families in Santalales: Balanophoraceae, Misodendraceae, Opiliaceae, Schoepfiaceae, Loranthaceae, Santalaceae (including Viscaceae), and Olacaceae. In 2010, however, new molecular data have made it possible to revise that conclusion, so that Aptandraceae, Balanophoraceae, Coulaceae, Erythropalaceae, Loranthaceae, Misodendraceae, Octonemaceae, Olacaceae, Opiliaceae, Santalaceae, Schoepfiaceae, Strombosiaceae, and Ximeniaceae are now recognized.
