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.
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.
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.
Schultesia benthamiana Klotzsch ex Griseb. Schultesia subcrenata Klotzsch ex Griseb.
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.