Neotropical Sarraceniaceae

Jon L.R. Every

Royal Botanic Gardens, Kew, UK. 

Description

Insectivourous herbs, rhizomatous or rarely woody. Leaves, sometimes dimorphic, alternate, in a basal rosette or on an upright sometimes branching stem, epiascidate leaves modified into a container used as an insect trap, petioles short, ventral side ridged, dorsal side extends into a cap covering trap opening, glands and retrorse hairs lining opening, lanceolate leaves sometimes present further into season, exstipulate. Inflorescence a terminal raceme, few-flowered. Flowers actinomorphic, hermaphrodite, nodding, bracteoles present, petaloid tepals 4(-9), imbricate, free; stamens 10-20, filaments short, free, anthers basifixed, dehiscing via short slits; ovary superior, syncarpous, carpels 3, 3(4)-locular, ovules numerous, style, short 3(4)-lobed. Fruit a capsule, globose, longitudinally dehiscing. Seeds numerous, small, often winged, sometimes hairy.

Notes on delimitation

  • Placed in the Ericales following molecular work carried out by Anderberg et al. (2002), in a clade with Ericaceae, Cyrillaceae, Clethraceae, Roridulaceae and Actinidiaceae forming a monophyletic group with the latter two.
  • Historically Sarraceniaceae have been placed in their own order the Sarraceniales sensu Takhtajan, the Theales sensu Thorne, and treated with other carnivorous plants in the Nepenthales sensu Cronquist.
  • The Heliamphora Benth. have been considered to be the most primitive genus of the Sarraceniaceae due to their comparatively poorly developed features.

Distribution in the Neotropics

  • Heliamphora Benth. is the only genus of the three Sarraceniaceae genera that grows in the Neotropics.
  • Around nine species are confined to the 'Tepuis' of remote Guayana Highlands in Venezuela, western Guyana and Northern Brazil.
  • They can form dense colonies in open, wet, nutrient-poor savannahs and heathlands.
  • The sandstone table-mountains (which reach heights of 3,000m above sea level) are incredibly isolated and flanked by vertical cliff faces and are consequently host to many endemic organisms - plus the odd intrepid explorer.

Distinguishing characters (always present)

Other important characters

  • Tepals usually white, sometimes flushed pink or red and turning pale green.
  • H. nutans Benth., H. minor Gleason and H. tatei Gleason can have erect woody stems.
  • Pitchers are filled with a digestive liquid (and some small insects).
  • Pitchers can appear red in colour due to the leaf veins.
  • Pitcher size varies greatly from a few cm tall to over one metre.

Key differences from similar families

  • Nepenthaceae only occur in the eastern hemisphere.
  • Cephalotaceae only occur in Australia.
  • Droseraceae and Roridulaceae use sticky glandular hairs to catch small animals.
  • Bromeliaceae have simple leaves usually covered with reduced spines, parallel venation and 3-merous flowers.

Number of genera

  • One genus Heliamphora with ca. nine species.

Status

  • Native.
  • Some species are endemic to specific table-top mountains.

General notes

  • The extra-floral nectaries which cover the opening of the pitcher attract insects and small animals to the trap where they become ensnared by downwards pointing trichomes and are subsequently digested by the plant.
  • Sarraceniaceae owes its epithet to Dr. Sarrasin, a Canadian physician.
  • Cultivated at RBG Kew since 1960.

Important literature

Anderberg, A. A., Rydin, C. and Kallersjo, M. 2002.  Phylogenetic relationships in the order Ericales S.L.: Analyses of molecular data from five genes from the plastid and mitochondrial genomes. American Journal of Botany 89(4):677-687

Kubitzki, K. 2004.  Sarraceniaceae, pp. 422-425. In: Kubitzki, K. (ed.), Families and genera of vascular plants vol. 6. Springer-Verlag, Berlin.

How to cite

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