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, while Dionaea and the aquatic Aldrovanda have hinged leaves that snap closed to trap prey. The highest diversity of Drosera species is in Australia (Conn 1995).

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
    |--Drosophyllum lusitanicum C95, D37
    |--Aldrovanda vesiculosa C95, C55
    |--Dionaea C95
    `--Drosera C95
         |--D. androsacea OS04
         |--D. arcturi A27
         |--D. banksii Brown ex DC. 1824 C95
         |--D. binata A27
         |--D. browniana G04
         |--D. bulbigena GK00
         |--D. bulbosa OS04
         |--D. burmanni Vahl 1794 [=D. burmannii (l. c.)] C95
         |--D. erythrorhiza GK00
         |--D. gigantea GK00
         |--D. glanduligera OS04
         |--D. heterophylla GK00
         |--D. indica Linnaeus 1753 C95
         |--D. longifolia D37
         |--D. lowriei G04
         |--D. macrantha OS04
         |--D. menziesii OS04
         |--D. neesii GK00
         |--D. paleacea GK00
         |--D. pallida GK00
         |--D. peltata Thunberg 1797 C95
         |    |--D. p. ssp. peltata C95
         |    `--D. p. ssp. auriculata C95
         |--D. petiolaris Brown ex DC. 1824 C95
         |--D. pulchella GK00
         |--D. pygmaea A27
         |--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. stenopetala A27
         |--D. stolonifera GK00
         |--D. subhirtella OS04
         `--D. uniflora D03

*Type species of generic name indicated

REFERENCES

[A27] Andersen, J. C. 1927. Popular names of New Zealand plants. Transactions and Proceedings of the New Zealand Institute 57: 905-977.

[C55] Candolle, A. de. 1855. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 2. Librairie de Victor Masson: Paris.

[C95] Conn, B. J. 1995. Droseraceae. In Handbooks of the Flora of Papua New Guinea vol. 3 (B. J. Conn, ed.) 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 Reports of the Princeton University Expeditions to Patagonia, 1896-1899, vol. 8 – Botany (W. B. Scott, ed.) 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.

[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.

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