Droseraceae

Round-leaved sundew Drosera rotundifolia growing among sphagnum, photographed by Noah Elhardt.

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 vesiculosa C95, LK14
    |--Dionaea muscipula C95, N91
    |--Palaeoaldrovanda CBH93
    |--Saxonipollis saxonicus CBH93
    |--Drosophyllum [Drosophyllaceae] C95
    |    `--D. lusitanicum D37
    `--Drosera Linnaeus 1753 A61
         |--D. androsacea OS04
         |--D. anglica [incl. D. longifolia] H93
         |--D. arcturi Hook. 1834 (see below for synonymy) A61
         |--D. atra Colenso 1899 (n. d.) A61
         |--D. banksii Brown ex DC. 1824 C95
         |--D. binata Labill. 1804 (see below for synonymy) A61
         |--D. brevicornis LK14
         |--D. broomensis LK14
         |--D. browniana G04
         |--D. bulbigena GK00
         |--D. bulbosa OS04
         |--D. burmanni Vahl 1794 [=D. burmannii (l. c.)] C95
         |--D. caduca LK14
         |--D. derbyensis LK14
         |--D. dilatatopetiolaris LK14
         |--D. erythrorhiza GK00
         |--D. gigantea GK00
         |--D. glanduligera OS04
         |--D. heterophylla GK00
         |--D. indica Linnaeus 1753 C95
         |--D. kenneallyi LK14
         |--D. lowriei G04
         |--D. macrantha OS04
         |--D. menziesii OS04
         |--D. minutula Colenso 1889 (n. d.) A61
         |--D. neesii GK00
         |--D. × obovata [D. anglica × D. rotundifolia] H93
         |--D. ordensis LK14
         |--D. paleacea GK00
         |--D. pallida GK00
         |--D. paradoxa LK14
         |--D. peltata Thunberg 1797 C95
         |    |--D. p. ssp. peltata C95
         |    `--D. p. ssp. auriculata C95 (see below for synonymy)
         |--D. petiolaris Brown ex DC. 1824 C95
         |--D. propinqua Cunn. 1840 A61
         |--D. pulchella GK00
         |--D. pygmaea DC. 1824 A61
         |--D. rosulata GK00
         |--D. rotundifolia Linnaeus 1753 C95
         |    |--D. r. var. rotundifolia C95
         |    `--D. r. var. bracteata Kern & Steen. 1955 C95
         |--D. spatulata Labill. 1805 [=D. spathulata (l. c.)] C95
         |--D. spilos LK00
         |--D. stenopetala Hook. f. 1852 A61
         |--D. stolonifera GK00
         |--D. subhirtella OS04
         |--D. subtilis LK14
         |--D. triflora Colenso 1890 (n. d.) A61
         `--D. uniflora D03

Drosera arcturi Hook. 1834 [incl. D. ligulata Colenso 1899, D. polyneura Colenso 1890, D. ruahinensis Colenso 1896] A61

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. auriculata C95 [=D. auriculata Backh. ex Planch. 1848 A61; incl. D. circinervia Colenso 1894 A61, D. stylosa Colenso 1896 A61]

*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).

[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 2^nd 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.

Last updated: 5 June 2022.