Overview of gentian tribal classification

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

Species:  About 220 species in 22 genera. Macrocarpaea is the largest genus.

Distribution: Neotropics only (American tropics): from Mexico to Bolivia and Paraguay.

Habitat:  Rainforests, cloud forests, savannas, grasslands, less often roadsides and other disturbed habitats. Lowland to high mountains. Many species only occur in very small, restricted areas.  

Characteristics:   Shrubs, subshrubs or perennial or annual herbs. Leaves sessile or petiolated. Inflorescences usually monochasially or dichotomously branched cymes, rarely axillary and/or with solitary flowers. Flowers (4–)5(–6)-merous, often large and showy. Calyces (fused sepals)  often thick/leathery, often with a thickened keel on the back of each sepal. Corollas (fused petals) tubular, funnel- or salvershaped, to campanulate. Stamens and style slightly zygomorphic in many species. When zygomorphic, the flowers have a slightly bent corolla tube with the anthers clustered in upper or lower part of the corolla mouth and a style bent toward the lower side of the corolla mouth. Anthers often with sterile apical appendages and strongly curved (or filaments sharply bent). Pollen as monads, tetrads, or polyads.  Stigma are often broadly bilamellate.  Fruit a thin or woody capsule.

Evolution and related plants:  The Helieae is most closely related to the tribes Gentianeae and Potalieae. Within Helieae, studies using molecular phylogenetic methods have shown that there are three major groups - the Macrocarpaea clade (Chorisepalum, Macrocarpaea, and Tachia), the Irlbachia clade (Irlbachia only), and the Symbolanthus clade (Aripuana, Calolisianthus, Chelonanthus, Symbolanthus, Tetrapollinia, Wurdackanthus).  

Economic uses:  Chelonanthus alatus is used for medicinal purposes in the Ecuadorian Amazon.

Notes - pollination: Bat-pollination is known from Chelonanthus alatus (Machado et al., 1998), and flowers reminiscent of bat-pollination occurs also in Macrocarpaea and Symbolanthus. Hummingbird-pollination is found in pink-flowered Symbolanthus, and is presumable also present in the red, tubular-flowered species of Lagenanthus, Lehmanniella, and Purdieanthus. Hawkmoth-type flowers are known from Aripuana and Chelonanthus.  

Included genera:

Adenolisianthus (Progel) Gilg (images)
Aripuana Struwe, Maas, & V. Albert (images)
Calolisianthus Gilg (images)
Celiantha Maguire (images)
Chelonanthus Gilg (images)
Chorisepalum Gleason & Wodehouse (images)
Helia Mart. (images)
Irlbachia Mart. (images)
Lagenanthus Gilg (images)
Lehmanniella Gilg (images)
Macrocarpaea (Griseb.) Gilg (images)
Neblinantha Maguire (images)
Prepusa Mart. (images)
Purdieanthus Gilg (images)
Rogersonanthus Maguire & B. M. Boom (images)
Senaea Taub. (images)
Sipapoantha Maguire & B. M. Boom (images)
Symbolanthus G. Don (images)
Tachia Aubl. (images)
Tetrapollinia Maguire & B. M. Boom (images)
Wurdackanthus Maguire (images)
Zonanthus Griseb. (images)

Bibliography: 

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.

Struwe, L., P. J. M. Maas, & V. A. Albert. 1997. Aripuana cullmaniorum, a new genus and species of Gentianaceae from white-sands of southeastern Amazonas, Brazil. Harvard Pap. Bot. 2: 235-253.

© Lena Struwe, 2002.