The Loganiaceae are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s classified in order

Gentianales Gentianales is an order of flowering plant, 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. Man ...

. The family includes up to 13

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

, 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 often used as a synony ...

. Poisonous properties are largely due to

alkaloids Alkaloids are a broad class of naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids. Alkaloids are produced by a large variety of organisms i ...

such as those found in ''

Strychnos ''Strychnos'' is a genus of flowering plants, belonging to the family Loganiaceae (sometimes Strychnaceae). The genus includes about 200 accepted species of trees and lianas. The genus is widely distributed around the world's tropics and is n ...

''.

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 boone ...

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

Oxford University Press Oxford University Press (OUP) is the publishing house of the University of Oxford. It is the largest university press in the world. Its first book was printed in Oxford in 1478, with the Press officially granted the legal right to print books ...

, Walton Street,

Oxford Oxford () is a City status in the United Kingdom, cathedral city and non-metropolitan district in Oxfordshire, England, of which it is the county town. The city is home to the University of Oxford, the List of oldest universities in continuou ...

OX2 6DP,

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

, 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 that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies ...

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 105 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 (species), cosm ...

Gelsemiaceae Gelsemiaceae is a family of flowering plants, belonging to the Order (biology), order Gentianales. The family contains only three genera: ''Gelsemium'', ''Mostuea'' and ''Pteleocarpa''. ''Gelsemium'' has three species, one native to Southeast Asi ...

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 fr ...

, Tetrachondraceae, Buddlejaceae, and

Gesneriaceae Gesneriaceae, the gesneriad family, is a family (biology), 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 Ges ...

. Some classification schemes, notably

Takhtajan Armen Leonovich Takhtajan or Takhtajian (; surname also transliterated Takhtadjan, Takhtadzhi︠a︡n or Takhtadzhian, pronounced takh-tuh-JAHN; 10 June 1910 – 13 November 2009), was a Soviet-Armenian botanist, one of the most important figu ...

'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. As of November 2023 ''

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

'' accepts 16 genera:Loganiaceae R.Br. ex Mart.
''

''. Accessed 17 November 2023.

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

* * {{Authority control Asterid families