Belongs within: Caryophyllales.
The Droseraceae are a family of about a hundred species of insectivorous plants, the vast majority of which are in the sundew genus Drosera. Drosera and Drosophyllum trap invertebrates by means of glandular hairs on the leaves whereas Dionaea and Aldrovanda have hinged leaves that snap closed to trap prey. Drosera has a cosmopolitan distribution with the highest diversity of species in Australia (Conn 1995). The Portuguese sundew Drosophyllum lusitanicum has linear leaves rising from a basal rosette that coil outwards when immature. The waterwheel plant Aldrovanda vesiculosa is a rootless, free-floating aquatic plant found in scattered locations around the Old World.
Characters (from Conn 1995): Small perennial or annual, terrestrial or aquatic, insectivorous herbs. Primary roots often reduced, base of stem with adventitious roots, sometimes a subterranean tuber or small rhizome present. Leaves spiral, sometimes whorled, often in a basal rosette, with pedicellate glands, marginal glands longest. Stipules present or absent. Inflorescence lateral or terminal, cymose, racemose or solitary. Bracts present or absent. Bracteoles absent. Flowers actinomorphic, bisexual. Calyx (4- or)5-merous, more or less imbricate; sepals more or less connate at base, persistent. Corolla (4- or)5-merous, more or less imbricate in bud; petals free, marcescent, persistent. Stamens hypogynous, 5, free, alternipetalous, persistent; filaments filiform; anthers bilocular, opening with two longitudinal slits, extrorse; pollen tricolpate or triporate. Gynoecium of 3-5 carpels; ovary superior, unilocular; placentation parietal; ovules usually many, anatropous, bitegmic; styles 3-5 (as many as placentas), free or connate, simple or divided; stigmas terminal, dry. Fruit a loculicidal capsule, 3-5-valved, surrounded by persistent calyx. Seeds numerous, small, spindle-shaped, endospermic; embryo straight; cotyledons straight.
<==Droseraceae |--Aldrovanda vesiculosaC95, LK14 |--Dionaea muscipulaC95, N91 |--PalaeoaldrovandaCBH93 |--Saxonipollis saxonicusCBH93 |--Drosophyllum [Drosophyllaceae]C95 | `--D. lusitanicumD37 `--Drosera Linnaeus 1753A61 |--D. androsaceaOS04 |--D. anglica [incl. D. longifolia]H93 |--D. arcturi Hook. 1834 [incl. D. ligulata Colenso 1899, D. polyneura Colenso 1890, D. ruahinensis Colenso 1896]A61 |--D. atra Colenso 1899 (n. d.)A61 |--D. banksii Brown ex DC. 1824C95 |--D. binata Labill. 1804 (see below for synonymy)A61 |--D. brevicornisLK14 |--D. broomensisLK14 |--D. brownianaG04 |--D. bulbigenaGK00 |--D. bulbosaOS04 |--D. burmanni Vahl 1794 [=D. burmannii (l. c.)]C95 |--D. caducaLK14 |--D. derbyensisLK14 |--D. dilatatopetiolarisLK14 |--D. erythrorhizaGK00 |--D. giganteaGK00 |--D. glanduligeraOS04 |--D. heterophyllaGK00 |--D. indica Linnaeus 1753C95 |--D. kenneallyiLK14 |--D. lowrieiG04 |--D. macranthaOS04 |--D. menziesiiOS04 |--D. minutula Colenso 1889 (n. d.)A61 |--D. neesiiGK00 |--D. × obovata [D. anglica × D. rotundifolia]H93 |--D. ordensisLK14 |--D. paleaceaGK00 |--D. pallidaGK00 |--D. paradoxaLK14 |--D. peltata Thunberg 1797C95 | |--D. p. ssp. peltataC95 | `--D. p. ssp. auriculataC95 (see below for synonymy) |--D. petiolaris Brown ex DC. 1824C95 |--D. propinqua Cunn. 1840A61 |--D. pulchellaGK00 |--D. pygmaea DC. 1824A61 |--D. rosulataGK00 |--D. rotundifolia Linnaeus 1753C95 | |--D. r. var. rotundifoliaC95 | `--D. r. var. bracteata Kern & Steen. 1955C95 |--D. spatulata Labill. 1805 [=D. spathulata (l. c.)]C95 |--D. spilosLK00 |--D. stenopetala Hook. f. 1852A61 |--D. stoloniferaGK00 | |--D. s. ssp. stoloniferaK90 | `--D. s. ssp. humilisK90 |--D. subhirtellaOS04 |--D. subtilisLK14 |--D. triflora Colenso 1890 (n. d.)A61 `--D. unifloraD03
Drosera binata Labill. 1804 [incl. D. cunninghamii Walp. 1842, D. dichotoma Banks & Sol. ex Smith in Rees 1809, D. flagellifera Colenso 1891, D. intermedia Cunn. 1840 non Hayne 1800]A61
Drosera peltata ssp. auriculataC95 [=D. auriculata Backh. ex Planch. 1848A61; incl. D. circinervia Colenso 1894A61, D. stylosa Colenso 1896A61]
*Type species of generic name indicated
References
[A61] Allan, H. H. 1961. Flora of New Zealand vol. 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. R. E. Owen, Government Printer: Wellington (New Zealand).
[CBH93] Collinson, M. E., M. C. Boulter & P. L. Holmes. 1993. Magnoliophyta (‘Angiospermae’). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 809–841. Chapman & Hall: London.
[C95] Conn, B. J. 1995. Droseraceae. In: Conn, B. J. (ed.) Handbooks of the Flora of Papua New Guinea vol. 3 pp. 49–55. Melbourne University Press: Carlton (Australia).
[D37] Dobzhansky, T. 1937. Genetics and the Origin of Species. Columbia University Press: New York.
[D03] Dusén, P. 1903. The vegetation of western Patagonia. In: Scott, W. B. (ed.) Reports of the Princeton University Expeditions to Patagonia, 1896–1899 vol. 8. Botany pp. 1–34. The University: Princeton (New Jersey).
[G04] Gibson, N. 2004. Flora and vegetation of the Eastern Goldfields Ranges: part 7. Middle and South Ironcap, Digger Rock and Hatter Hill. Journal of the Royal Society of Western Australia 87 (2): 49–62.
[GK00] Gibson, N., & G. J. Keighery. 2000. Flora and vegetation of the Byenup-Muir reserve system, south-west Western Australia. CALMScience 3 (3): 323–402.
[H93] Hickman, J. C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press: Berkeley (California).
[K90] Keighery, G. J. 1990. Vegetation and flora of Shark Bay, Western Australia. In: Berry, P. F., S. D. Bradshaw & B. R. Wilson (eds) Research in Shark Bay: Report of the France-Australe Bicentenary Expedition Committee pp. 61–87. Western Australian Museum.
[LK00] Lowrie, A., & K. F. Kenneally. 2000. Three new species of Stylidium (Stylidiaceae) from south-west Western Australia. Nuytsia 13: 293–302.
[LK14] Lyons, M. N., G. J. Keighery, L. A. Gibson & T. Handasyde. 2014. Flora and vegetation communities of selected islands off the Kimberley coast of Western Australia. Records of the Western Australian Museum Supplement 81: 205–244.
[N91] Norris, K. R. 1991. General biology. In: CSIRO. The Insects of Australia: A textbook for students and research workers 2nd ed. vol. 1 pp. 68–108. Melbourne University Press: Carlton (Victoria).
[OS04] Obbens, F. J., & L. W. Sage. 2004. Vegetation and flora of a diverse upland remnant of the Western Australian wheatbelt (Nature Reserve A21064). Journal of the Royal Society of Western Australia 87 (1): 19–28.