Loganiaceae Explained

The Loganiaceae are a family of flowering plants classified in order Gentianales. The family includes up to 13 genera, distributed around the world's tropics. There are not any great morphological characteristics to distinguish these taxa from others in the order Gentianales.

Many members of the Loganiaceae are extremely poisonous, causing death by convulsion. Poisonous properties are largely due to alkaloids such as those found in Strychnos. Glycosides are also present as loganin in Strychnos.^[1]

Earlier treatments of the family have included up to 29 genera. Phylogenetic studies have demonstrated that this broadly defined Loganiaceae was a polyphyletic assemblage, and numerous genera have been removed from Loganiaceae to other families (sometimes in other orders), e.g., Gentianaceae, Gelsemiaceae, Plocospermataceae, Tetrachondraceae, Buddlejaceae, and Gesneriaceae. Some classification schemes, notably Takhtajan'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.^{[2] [3]} A more recent study considers some Labordia species synonymous with Geniostoma,^[4] resulting in 12 genera in other sources.^[5] As of November 2023 Plants of the World Online accepts 16 genera:^[6]

Adelphacme Antonia Pohl Bonyunia R. H. Schomb. ex Progel Gardneria Wall. Geniostoma J. R. Forst. & G.Forst. (syn. Labordia Gaudich.) Logania R.Br. Mitrasacme Labill. Mitreola L.

Neuburgia Blume Norrisia Gardner Orianthera Phyllangium Schizacme Spigelia L. Strychnos L. Usteria Willd.

Excluded genera

Androya H.Perrier -> Scrophulariaceae Anthocleista Afzel. ex R.Br. -> Gentianaceae Buddleja L. -> Scrophulariaceae Desfontainia Ruiz & Pav. -> Columelliaceae Emorya Torr. -> Scrophulariaceae Fagraea Thunb. -> Gentianaceae Gelsemium Juss. -> Gelsemiaceae Gomphostigma Turcz. -> Scrophulariaceae

Mostuea Didr. -> Gelsemiaceae Nuxia Comm. ex Lam. -> Stilbaceae Peltanthera Benth. -> Gesneriaceae Plocosperma Benth. -> Plocospermataceae Polypremum L. -> Tetrachondraceae Potalia Aubl. -> Gentianaceae Retzia Thunb. -> Stilbaceae^[7]

References

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

Notes and References

1. Flowering Plants of the World by consultant editor Vernon H. Heywood, 1978, Oxford University Press, Walton Street, Oxford OX2 6DP, England,
2. Backlund . Maria . Oxelman . Bengt . Bremer . Birgitta . Phylogenetic relationships within the Gentianales based on NDHF and RBCL sequences, with particular reference to the Loganiaceae . . July 2000 . 87 . 7 . 1029–1043 . 10.2307/2657003. 2657003 . 10898781 .
3. Web site: GRIN Genera Records of Loganiaceae . Germplasm Resources Information Network . United States Department of Agriculture . 2010-12-15 . https://web.archive.org/web/20041118031741/http://www.ars-grin.gov/cgi-bin/npgs/html/gnlist.pl?667 . 2004-11-18 . dead .
4. Gibbons . Kerry L. . Henwood . Murray J. . Conn . Barry J. . Phylogenetic relationships in Loganieae (Loganiaceae) inferred from nuclear ribosomal and chloroplast DNA sequence data . . 25 . 5 . 331–340 . 2012 . 2017-03-19 . 10.1071/sb12002. 85322573 .
5. Angiosperm Phylogeny Group . 2009 . An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III . Botanical Journal of the Linnean Society . 161 . 2 . 105–121 . 10.1111/j.1095-8339.2009.00996.x . free . 10654/18083 . free .
6. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30002038-2 Loganiaceae R.Br. ex Mart.
7. Web site: GRIN genera sometimes placed in Loganiaceae . Germplasm Resources Information Network . United States Department of Agriculture . 2010-12-15 . https://web.archive.org/web/20041118031719/http://www.ars-grin.gov/cgi-bin/npgs/html/gnothlist.pl?667 . 2004-11-18 . dead .