Neotropical Droseraceae

Jon L.R. Every

University of Plymouth, U.K. 

Description

Carnivorous herbs. Leaves alternate, forming basal rosettes, rarely alternate or whorled on short stems, , simple, with sticky glandular trichomes (appearing as tentacles) present on lamina and petiolesmargins entire; stipulate (can be scaly or leafy). Inflorescence terminal, cymose, paniculate, racemose, rarely solitary. Flowers actinomorphic, bisexual, ebracteate; sepals (4-)5-8(-12), imbricate, persistent; petals (4-)5-8(-12), polypetalous, alternating with short-lived sepals; stamens (4-)5(-20),  free from and alternating with perianth, anthers extrorse, longitudinally dehiscent; ovary superior, syncarpous, carpels (2-)3(-5); styles (2-)3(-5), much-divided. Fruits loculicidal capsules. Seeds  3 to numerous.

Notes on delimitation

  • Regularly allied with other carnivorous plant groups such as the Nepenthaceae and Sarraceniaceae.
  • Currently placed in the Caryophyllales in a group which includes the extra-Neotropical Nepenthaceae, the monotypic (and recently included member of the Droseraceae) Drosopyllaceae, plus Dioncophyllaceae and Ancistrocladaceae (APG III & Stevens 2008).

Distribution in the Neotropics

  • Have adapted to grow in wet areas with very few available nutrients - such as bogs and swamps.
  • Found from sea-level to altitudes over 3,000m throughout the Neotropics.

Distinguishing characters (always present)

  • Modified, insectivorous leaves with enzyme-secreting, tentacle-like glandular trichomes.

Key differences from similar families

  • The Neotropical representatives of the Sarraceniaceae, Heliamphora Benth, have highly modified leaves called 'amphores' which are employed as insect-traps.

Number of genera

  • 1: Drosera with ca. 20 species.

Status

  • Native.

General notes

  • Known as the 'Sundews'.

Important literature

Culham, A. 2007. Droseraceae. In: Heywood V.H., Brummitt R.K., Culham A. and Seberg O. (eds.). Flowering Plant Families of the World. Pp. 132-133. Royal Botanic Gardens, Kew.

Mireya, D. & Correa, A. 2004. Droseraceae. In: Smith, N., Mori, S.A., Henderson, A., Stevenson, D.W. and Heald, S.V. (eds.). Flowering Plants of the Neotropics. Pp.132-133. The New York Botanical Garden, Princeton University Press, Princeton.

Stevens, P.F. 2008. Angiosperm Phylogeny Website. Version 9 onwards. http://www.mobot.org/MOBOT/research/APweb/.

Watson, L. and Dallwitz, M.J. (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version 3rd March 2009. http://delta-intkey.com.

How to cite

Every, J.L.R. (2009). Neotropical Droseraceae. 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/Droseraceae.htm.