The Loganiaceae are a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s classified in order

Gentianales Gentianales is an order of flowering plants, included within the asterid clade of eudicots. It comprises more than 20,000 species in about 1,200 genera in 5 families. More than 80% of the species in this order belong to the family Rubiaceae. Ma ...

. The family includes up to 13

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

, distributed around the world's tropics. There are not any great morphological characteristics to distinguish these taxa from others in the order

. Many members of the Loganiaceae are extremely poisonous, causing death by

convulsion A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. Because epileptic seizures typically include convulsions, the term ''convulsion'' is sometimes used as a s ...

. Poisonous properties are largely due to

alkaloids Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar st ...

such as those found in ''

Strychnos ''Strychnos'' is a genus of flowering plants, belonging to the family Loganiaceae (sometimes Strychnaceae). The genus includes about 100 accepted species of trees and lianas, and more than 200 that are as yet unresolved. The genus is widely dis ...

''.

Glycosides In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...

are also present as

loganin Loganin is one of the best-known of the iridoid glycosides. It is named for the Loganiaceae, having first been isolated from the seeds of a member of that plant family, namely those of ''Strychnos nux-vomica''. It also occurs in ''Alstonia boonei' ...

in ''Strychnos''.Flowering Plants of the World by consultant editor Vernon H. Heywood, 1978,

Oxford University Press Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books ...

, Walton Street,

Oxford Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the ...

OX2 6DP,

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

, Earlier treatments of the family have included up to 29 genera. Phylogenetic studies have demonstrated that this broadly defined Loganiaceae was a

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...

assemblage, and numerous genera have been removed from Loganiaceae to other families (sometimes in other orders), e.g.,

Gentianaceae Gentianaceae is a family of flowering plants of 103 genera and about 1600 species. Etymology The family takes its name from the genus '' Gentiana'', named after the Illyrian king Gentius. Distribution Distribution is cosmopolitan. Characteri ...

Gelsemiaceae Gelsemiaceae is a family of flowering plants, belonging to the order Gentianales. The family contains only three genera: ''Gelsemium'', ''Mostuea'' and ''Pteleocarpa''. ''Gelsemium'' has three species, one native to Southeast Asia and southern C ...

Plocospermataceae ''Plocosperma'' is the sole genus in the Plocospermataceae,Stevens, P.F. (2001 onwards)Plocospermataceae ''Angiosperm Phylogeny Website'', retrieved 2013-08-15 a family of flowering plant Flowering plants are plants that bear flowers and fru ...

Tetrachondraceae Tetrachondraceae is a plant family in the order Lamiales The order Lamiales (also known as the mint order) are an order in the asterid group of dicotyledonous flowering plants. It includes about 23,810 species, 1,059 genera, and is divided in ...

Buddlejaceae Buddlejaceae is a family of flowering plants that is not currently recognized by the Angiosperm Phylogeny Group, but as of 2016 it is being used by many botanists as one of several small families that divide the Lamiales. Phylogenetic reconstruc ...

, and

Gesneriaceae Gesneriaceae, the gesneriad family, is a family of flowering plants consisting of about 152 genera and ca. 3,540 species in the tropics and subtropics of the Old World (almost all Didymocarpoideae) and the New World (most Gesnerioideae), with ...

. Some classification schemes, notably

Takhtajan Armen Leonovich Takhtajan or Takhtajian ( hy, Արմեն Լևոնի Թախտաջյան; russian: Армен Леонович Тахтаджян; surname also transliterated Takhtadjan, Takhtadzhi︠a︡n or Takhtadzhian, pronounced takh-tuh-JA ...

's, break the remaining Loganiaceae even further, into as many as four families; Strychnaceae, Antoniaceae, Spigeliaceae and Loganiaceae.

Genera

Some sources indicate the family consists of 13 genera. A more recent study considers some ''Labordia'' species synonymous with ''Geniostoma'', resulting in 12 genera in other sources.

Excluded genera

References

* Struwe, L., V. A. Albert, and B. Bremer (1994). "Cladistics and family level classification of the Gentianales". ''Cladistics'' 10: 175–205.

External links

* * {{Taxonbar, from=Q500842 Asterid families