Mats H.G. Gustafsson
Department of Biological Sciences, Aarhus University, Denmark.
Shrubs or trees, glarous. Leaves alternate, entire. Inflorescences cymose or flowers solitary. Flowers with 5 sepals; petals 5, free, contorted, white or pink; stamens numerous, sometimes in 5 antepetalous fascicles, anthers basifixed; ovary superior, consisting of 3 - 5 carpels, styles free or basally fused; placentation central. Fruits septicidal capsules with 3-5 locules. Seeds small and numerous, often winged.
Notes on delimitation
- The Bonnetiaceae are related to the Clusiaceae and its segregate families Calophyllaceae and Hypericaceae.
- In this group of families also belong the Podostemaceae, a group of highly specialized aquatics found in fast-flowing streams.
- The closest relatives of the Bonnetiaceae are, according to the most recent molecular results, the Clusiaceae sensu stricto (Ruhfel et al. 2011).
Distribution in the Neotropics
- Most species of Bonnetiaceae are confined to the Guayana region, but the Northern Andes, Eastern Brazil and Cuba have one species each.
Distinguishing characters (always present)
- Leaves are spirally inserted, entire, exstipulate and sessile to subsessile.
- Leaf margins are either smooth or finely serrate.
- Flower buds are somewhat pointed.
- Stamens are numerous and basifixed.
Other important characters
Key differences from similar families
- Alternate-leaved members of the Clusiaceae may be similar, but they either have exudate or anther-glands, both absent in the Bonnetiaceae.
Number of genera
- Two: Archytaea Mart &BonnetiaMart.
Useful tips for generic identification
Key to genera of Neotropical Bonnetiaceae
Notable genera and distinguishing features
- Bonnetia, with about 30 neotropical species, is a characteristic component of the vegetation of the tepuis, the sandstone plateaus of the Guayana shield. They are often small trees with leaves that may resemble those of monocotyledons in being sessile with parallel veins (actually secondary veins parallel to the midvein).
Ruhfel, B., V. Bittrich, C. Bove, M. H. G. Gustafsson, C. Philbrick, R. Rutishauser, Z. Xi and C. Davis. 2011. Phylogeny of the Clusioid clade (Malpighiales): evidence from the plastid and mitochondrial genomes. American Journal of Botany 98: 306-325.Stevens, P. F. 2007. Hypericaceae. In K. Kubitzki (ed.) Families and Genera of Vascular Plants. Volume IX: 194-201. Springer-Verlag, Berlin. Steyermark, J. A. 1984. Theaceae (Bonnetiaceae). In: Flora of the Venezuelan Guayana, I. Annals of the Missouri Botanical Garden 71: 297-340.
How to cite
Gustafsson, M.H.G. (2013). Neotropical Bonnetiaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Bonnetiaceae.htm.