Overview of gentian tribal classification

Classification list arranged by genus name
The convoluted history of the name Lisianthus

Species:  About 150 species in 13 genera. Fagraea is the largest genus.

Distribution: Tropical areas in South and Central America, Africa, Madagascar, Asia, Pacific, and northern Australia.

Habitat:  Rainforests, savannas, grasslands, less often roadsides and other disturbed habitats. 

Characteristics:   Trees, lianas, shrubs, or herbs. Interpetiolar sheath or prominent line common in Anthocleista, Lisianthius, Potalia, and most Fagraea. Inflorescences are dichasial cymes, clusters, umbels, or flowers are solitarily. Flowers (3-)4-5(8-16)-merous.  Stamens often with various appendages at their bases. Pistil is sessile, often with nectary disk at base. Stigma capitate, slightly bilobed, or broadly bilamellate. Fruit a capsule or fleshy berry.

Evolution and related plants:  The Potalieae is most closely related to the tribes Gentianeae and Helieae. Within Helieae, studies using molecular phylogenetic methods have shown that there are three major clades; The subtribe Faroinae (Enicostema, Neurotheca and related genera), the subtribe Lisianthiinae (Lisianthius only), and the subtribe Potaliinae (Anthocleista, Fagraea, and Potalia).  

Economic uses:  Anthocleista and Potalia have many ethnobotanical uses, and are primarily used to treat fevers and inflammations.  Fagraea is often used for decoration and perfumes, and some species are also used for timber.

Notes:  Anthocleista, Fagraea, and Potalia (= subtribe Potaliinae) were earlier included in the plant family Loganiaceae, but already Bureau (1856) suggested that they should be placed in the Gentianaceae.  Data gathered from phylogenetic studies in the 1990's also placed these three genera inside the Gentianaceae and the transfer was made in 1994 (Struwe et al., 1994).  These genera have many characters in common with the gentians, such as the presence of the chemicals xanthones, special seco-iridoids, and no alkaloids, contort corolla lobe aestivation, and a large deletion in the trnL intron gene.  However, Potalia and Anthocleista have pollen and flowers that are different from most other gentians.

Included genera:

Anthocleista R. Br. (images)
Congolanthus A. Raynal
Djaloniella P. Taylor
Enicostema Blume (images)

Fagraea Thunb. (images)
Faroa Welw.
Karina Boutique
Lisianthius P. Browne (images)

Neurotheca Salisb. ex Benth. (images)
Oreonesion A. Raynal

Potalia Aubl. (images)
Pycnosphaera Gilg
Urogentias Gilg & Gilg-Ben.

Bibliography:  

Leeuwenberg, A. J. M. & P. W. Leenhouts. 1980. Taxonomy. Pp. 8-96. In: A. J. M. Leeuwenberg, editor. Engler and Prantl’s Die natürlichen Pflanzenfamilien, Angiospermae: Ordnung Gentianales, Fam. Loganiaceae, vol. 28b (1). Duncker and Humblot, Berlin.

Struwe, L., J. W. Kadereit, J. Klackenberg, S. Nilsson, M. Thiv, K. B. von Hagen, & V. A. Albert. 2002. Systematics, character evolution, and biogeography of Gentianaceae, including a new tribal and subtribal classification. Pp. 21-309. In: L. Struwe & V. A. Albert (eds.), Gentianaceae: Systematics and Natural History, Cambridge University Press, Cambridge.

© Lena Struwe, 2003.