Malpighiales

The Malpighiales comprise one of the largest orders of flowering plants, containing about 16,000 species, about 7.8% of the eudicots. The order is very diverse, containing plants as different as the willow, violet, poinsettia, and coca plant, and are hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems based only on plant morphology. Molecular clock calculations estimate the origin of stem group Malpighiales at around 100 million years ago (Mya) and the origin of crown group Malpighiales at about 90 Mya. The Malpighiales are divided into 32 to 42 families, depending upon which clades in the order are given the taxonomic rank of family. In the APG III system, 35 families are recognized. Medusagynaceae, Quiinaceae, Peraceae, Malesherbiaceae, Turneraceae, Samydaceae, and Scyphostegiaceae are consolidated into other families. The largest family, by far, is the Euphorbiaceae, with about 6300 species in about 245 genera. In a 2009 study of DNA sequences of 13 genes, 42 families were placed into 16 groups, ranging in size from one to 10 families. Almost nothing is known about the relationships among these 16 groups. Malpighiales and Lamiales are the two large orders whose phylogeny remains mostly unresolved. Malpighiales is a member of a supraordinal group called the COM clade, which consists of the orders Celastrales, Oxalidales, and Malpighiales. Some describe it as containing a fourth order, Huales, separating the family Huaceae into its own order, separate from Oxalidales. Some recent studies have placed Malpighiales as sister to Oxalidales sensu lato (including Huaceae), while others have found a different topology for the COM clade. The COM clade is part of an unranked group known as Fabidae or eurosids I. The fabids, in turn, are part of a group that has long been recognized, namely, the rosids. The great French botanist Charles Plumier named the genus Malpighia in honor of Marcello Malpighi's work on plants; Malpighia is the type genus for the Malpighiaceae, a family of tropical and subtropical flowering plants. The family Malpighiaceae was the type family for one of the orders created by Jussieu in his 1789 work Genera Plantarum. Friedrich von Berchtold and Jan Presl described such an order in 1820. Unlike modern taxonomists, these authors did not use the suffix 'ales' in naming their orders. The name 'Malpighiales' is attributed by some to Carl von Martius. In the 20th century, it was usually associated with John Hutchinson, who used it in all three editions of his book, The Families of Flowering Plants. The name was not used by those who wrote later, in the 1970s, '80s, and '90s.