Neotropical Haptanthaceae

Jon L.R. Every

Royal Botanic Gardens, Kew, U.K. 


Evergreen broad-leaved tree (or shrub?). Leaves opposite, simple, entire, glabrous; estipulate. Inflorescence axillary, cymose, pedunculate. Flowers unisexual, monoecious, bracteate; staminate flowers with 2 leaf-like stamens and tepals absent, or 2 tepals with adnate stamens, anthers dehiscing via longitudinal slits, dorsifixed; pistillate flowers with 4 tepals, ovary superior, syncarpous, carpels 3, placentation parietal, stigmas 3. Fruit unknown.

Notes on delimitation

  • Described in 1989 as Haptanthus hazlettii Goldberg & C. Nelson and placed in its own family.
  • Placed in the Buxales by the APG on morphological grounds (Stevens 2008).

Distribution in the Neotropics

  • Found on a single occasion in the rainforest of central Honduras in 1980, rediscovered in April 2010.

Distinguishing characters (always present)

Key differences from similar families

Number of genera

  • 1: Haptanthus hazlettii.

Important literature

Goldberg, A. & Nelson, C. 1989. Haptanthus, a New Dicotyledonous Genus from Honduras. Systematic Botany: 14(1): 16-19.

Heywood, V.H. 2007. Haptanthaceae. In: V.H. Heywood, R.K. Brummitt, A. Culham and O. Seberg (eds.). Flowering plant families of the world. P.164. Royal Botanic Gardens, Kew.

Maas, P.J.M. & Westra, L.Y.Th. 2005. Neotropical Plant Families. 358 pp. 3rd ed. A.R.G. Gantner Verlag K.G., Ruggell.

Stevens, P.F. 2008. Angiosperm Phylogeny Website. Version 9 onwards.

Stevens, P.F. & Doust, A.N. 2005. A Reinterpretation of the Staminate Flowers of Haptanthus. Systematic Botany 30(4): 779-785.

How to cite

Every, J.L.R. (2009). Neotropical Haptanthaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.