Droseraceae

Droseraceae

Synonymy

Droseraceae Salisb., Parad. Lond. 2: ad t. 95. 1808 sec. APG III (2009)

Introduction

The family includes perennial or annual carnivorous herbs and sometimes submerged aquatics (Kubitzki 2003b) characterised by having perception of tactile and chemical stimuli, leaf blade and tentacle movement, and genetically by a loss of the rpl2 intron (Heubl & al. 2006). The family comprises three genera, two of them are monotypic: Aldrovanda L. is distributed in Eurasia, southeastern Africa and north-eastern Australia and Dionaea Sol. ex J. Ellis, endemic to the southeastern United States. Drosera L. is cosmopolitan and comprises probably more than 100 species (Kubitzki 2003b; Rivadavia & al. 2003). The family is well-known to attract, capture, retain, and digest small prey animals (mainly small arthropods) with active snap-traps (Aldrovanda [= waterwheel plant] and Dionaea [= Venus's flytrap]) or with active sticky flypaper traps (Drosera [= sundews]) and to absorb the resulting nutrients (Poppinga 2013).
The relationships of Droseraceae to the other carnivorous families of the Caryophyllales remain unclear; the results of several molecular phylogenetic studies resulted in three main hypotheses: Droseraceae as sister of Nepenthaceae (e.g. Nandi & al. 1998: rbcL; Cuénoud & al. 2000; Brockington & al. 2009: combined nuclear and plastid data; Schäferhoff & al. 2009: petD); Droseraceae as sister of a clade including Drosophyllaceae + [Ancistrocladaceae + Dioncophyllacae] (e.g. Schäferhoff & al. 2009: petD) and Droseraceae as sister of the rest of the carnivorous families (e.g. Meimberg & al. 2000: partial matK; Schäferhoff & al. 2009: complete matK; Renner & Spetcht 2011: combined nuclear, ribosomal and plastid data).