Gentianaceae
Description
Herbs, sometimes shrubs or small trees, or saprophytic herbs; glabrous (rarely hairy). Leaves opposite (rarely alternate or whorled), decussate, sometimes connate at base; without stipules but often with interpetiolar lines or ocreas; blades simple, entire, scale-like in saprophytic species. Inflorescences axillary or terminal dichasia, cymes, spikes or clusters, sometimes reduced to one flower. Flowers actinomorphic or slightly zygomorphic, bisexual, (3-)4-5(-6-12)-merous; calyx lobes fused at base, seldom free, persistent in fruit (rarely not), imbricate or valvate; corolla sympetalous, salver-shaped, funnel-shaped, campanulate, tubular or rotate, lobes contorted; stamens as many as corolla lobes and alternating with them, inserted in corolla tube (rarely in sinuses), mostly not exserted beyond corolla, anthers dorsifixed, versatile, 2 thecae often diverging at base, longitudinally dehiscent; pollen in monads, tetrads or polyads; pistil 1, ovary superior, 1(-2)-locular, 2 parietal or axile placentas, ovules numerous, anatropous, style 1, stigma capitate or 2-lobed. Fruits either a septicidally 2-valved capsule (rarely 4-valved) or a berry; seeds numerous, endosperm usually copious.
Distribution
Guianas present, Neotropics present, worldwide present
About 1700 species in ca. 97 genera (Struwe et al., 2002) worldwide; in the Neotropics about 430 species in 47 genera; in the Guianas, 54 species in 19 genera.
Taxonomy
The GENTIANACEAE is divided into 6 monophyletic tribes, of which 4 are present in the Guianas: CHIRONIEAE , HELIEAE , POTALIEAE , and SACCIFOLIEAE (Struwe et al., 2002). Coutoubea and Schultesia are placed in subtribe Coutoubeinae in CHIRONIEAE . The tribe with the most genera is HELIEAE , which includes Celiantha , Chelonanthus , Chorisepalum , Irlbachia , Macrocarpaea , Rogersonanthus , Sipapoantha , Symbolanthus , Tachia , and Tetrapollinia . Tribe POTALIEAE is represented by Potalia in subtribe Potaliinae , and Enicostema and Neurotheca in subtribe Faroinae . Finally, the smaller tribe SACCIFOLIEAE includes Curtia , Tapeinostemon , and Voyriella . The saprophytic genus Voyria has not yet been classified into a tribe due to lack of phylogenetic data and its enigmatic morphological and molecular characters.
Lectotypification:
Notes
The circumscription of GENTIANACEAE in this work follows the classification of Struwe et al. (2002). The genus Potalia has been moved from LOGANIACEAE and is included in GENTIANACEAE . Several genera are under revision or have recently been revised, which has changed generic or species circumscriptions. The Irlbachia complex has been divided into segregate genera, such as Celiantha , Chelonanthus , Irlbachia , Rogersonanthus and Tetrapollinia , and Chelonanthus alatus is here segregated into several species.