Click on images to enlarge
dense infestation, developing from a single large clump-forming colony (Photo: Sheldon Navie)
young plant forming a loose basal rosette of leaves (Photo: Sheldon Navie)
older plant with more obviously lobed leaves (Photo: Sheldon Navie)
habit in flower (Photo: Sheldon Navie)
leaf undersides and creeping underground stems (Photo: Sheldon Navie)
finely grooved stems and leaf stalks, with a see-through 'sheath' at the base (Photo: Sheldon Navie)
close-up of the arrowhead-shaped leaf with two basal lobes (Photo: Sheldon Navie)
male flowers, borne in groups of 5-8 along the branches of the flower clusters (Photo: Sheldon Navie)
close-up of male flowers (Photo: Greg Jordan)
branched female flower clusters (Photo: Sheldon Navie)
close-up of female flowers with feathery stigmas (Photo: Greg Jordan)
close-up of immature fruit (Photo: Sheldon Navie)
close-up of seeds (Photo: Steve Hurst at USDA PLANTS Database)
'seedlings', or more accurately young shoots emerging from the creeping underground stems (Photo: Sheldon Navie)
Acetosella vulgaris Fourr.
Acetosa angiocarpa (Murb.) . L ve (misapplied)
Acetosella vulgaris Fourr. subsp. pyrenaica (Pourr. ex Lapeyr.) . L ve
Rumex acetosella L.
Rumex acetosella L. subsp. acetosella
Rumex acetosella L. subsp. pyrenaica (Pourr. ex Lapeyr.) Akeroyd
Rumex acetosella L. var. vulgaris Koch
Rumex angiocarpus Murb. (misapplied)
Rumex pyrenaica Pourr. ex Lapeyr.
Native to western and central Europe (i.e. Denmark, Ireland, Norway, Sweden, the UK, Austria, Belgium, Czechoslovakia, Germany, Switzerland, Italy, Yugoslavia, France and Spain).
This species is very widely naturalised in southern and eastern Australia. It is most common in south-eastern Queensland, eastern New South Wales, the ACT, Victoria, Tasmania, south-eastern South Australia and south-western Western Australia. Also occasionally naturalised in the coastal districts of central and northern Queensland, and in other parts of New South Wales and South Australia.
Sheep sorrel (Acetosella vulgaris) is a weed of crops, pastures, gardens, footpaths, roadsides, coastal areas, wetlands, heathlands, grasslands, open woodlands and alpine areas. It is most common in the temperate regions of Australia, but is also present in sub-tropical areas.
- a small clump-forming herbaceous plant with an extensive underground root system.
- its stalked leaves are distinctively arrowhead-shaped, with two basal lobes.
- its tiny green or reddish flowers are borne in branched clusters at the top of upright flowering stems.
- separate male and female flowers are borne on separate plants.
- its tiny fruit (1-1.5 mm long) are three-sided and remain hidden inside the remains of the flowers.
The two seed-leaves (i.e. cotyledons) are elongated or oval in shape (i.e. narrowly-elliptic) with rounded tips (i.e. obtuse apices). They ar hairless (i.e. glabrous) with tapering bases and short stalks (i.e. petioles). The first true leaves have longer stalks (i.e. petioles) and are broader, being either oval or egg-shaped in outline (i.e. elliptic or ovate). They are also hairless (i.e. glabrous) and have somewhat pointed tips (i.e. acute apices). Late leaves are progressively more triangular in shape, with pointed lobes at their bases.
Stems and Leaves
This slender, clump-forming, herb develops an extensive network of branching underground stems (i.e. rhizomes), off which numerous aboveground shoots atre produced each year. Plants initially form loose, few-leaved, rosettes and then eventually develop upright (i.e. erect) flowering stems. These flowering stems are slender, green, hairless (i.e. glabrous), and have tiny grooves running lengthwise.
The alternately arranged leaves are borne on stalks (i.e. petioles) ranging from 0.5-7 cm long. These leaves (1-8 cm long and 0.5-3 cm wide) are somewhat elongated and shaped like arrowheads (i.e. hastate) with undulating, but otherwise entire margins. The two lobes at the base of the leaves vary in size and shape depending on the leaves position on the plant, but are usually about 15-25 mm long. The leaves are hairless (i.e. glabrous) with pointed tips (i.e. acute apices). The base of each leaf stalk (i.e. petiole) also has dilated margins that form a see-through membranous sheath called an 'ochrea' which usually encloses part of the stem.
Flowers and Fruit
The flowers are small, green or more commonly reddish in colour, and arranged in upright (i.e. erect) branched clusters at the tips of the stems (i.e. in terminal panicles). Separate male and female flowers are borne on separate plants (i.e. this species is dioecious). Flowers are borne in small groups (i.e. whorls) of 5-8 along the flowering branches. They are about 1-2 mm long and are borne on short stalks (i.e. pedicels) up to 2 mm long. Each flower has three tiny 'sepals' and three 'petals' (i.e. inner and outer perianth segments). Male flowers also have six yellow stamens, while female flowers have an ovary topped with a three-branched stye and feathery (i.e. fimbriate) stigmas. Flowers occurs mainly during spring and early summer (i.e. from September to December).
The tiny fruit is a three-sided nut 1-1.5 mm long. These fruit are smooth and shiny, remain hidden inside the remains of the flowers parts, and turn brown as they mature.
Reproduction and Dispersal
Thes seeds maybe spread by wind, water and animals that eat the seeds. They may also be dispersed in mud adhering to animals and vehicles, in soil, and in contaminated agricultural produce (e.g. fodder, pasture seed and grain). Seeds and rhizomes can also be spread in dumped garden waste, in nursery pots, and during cultivation.
Sorrel (Acetosella vulgaris) is regarded as an important environmental weed in south-eastern Australia, particularly in Victoria and New South Wales. While this species is also known as a weed of crops and pastures, it invades a wide variety of natural habitats (e.g. dry coastal vegetation, heathlands, heathy woodlands, grasslands, grassy woodlands, dry sclerophyll forests, wetlands, rocky outcrops, and sub-alpine and alpine vegetation).
It is of most concern in the sub-alpine and alpine regions of south-eastern Australia, where it can form dense carpets, and is thought to be the most common weed species in the treeless vegetation of the Australian Alps. Sorrel (Acetosella vulgaris) is particularly troublesome in the Kosciuszko alpine area in the southern tablelands region of New South Wales, where it is the most widespread non-native colonising species. It primarily invades bare areas and disturbed sites, but can eventually be replaced by native species is soem situations.
Sorrel (Acetosella vulgaris) is considered to pose a threat to the integrity of one or more vegetation formations in Victoria. It is a common weed of buloke grassy woodlands, riparian shrublands and montane riparian woodlands in this state, and has been recorded in numerous conservation areas (e.g. Organ Pipes National Park, Morwell National Park, Yarra Bend Park, Boonderoo Nature Conservation Reserve, Dreeite Nature Conservation Reserve, Pomborneit North Nature Conservation Reserve, Rice Nature Reserve, Dans Nature Reserve and Phillip Island Nature Park). It is also a commonly reported weed species in vegetation supporting almost all of the remaining known populations of the vulnerable Euroa guinea-flower (Hibbertia humifusa subsp. erigens). This spcies is endemic to north-eastern Victoria, and weed invasion by sorrel (Acetosella vulgaris), and other weed species, is considered to be the greatest threat to almost all populations of this native plant.
Sorrel (Acetosella vulgaris) is also a principal weed species in tableland basalt forests in the Sydney Basin and South Eastern Highlands bioregions of New South Wales. This vegetation type is listed as an endangered ecological community by the NSW Scientific Committee, and is being threatened by weed invasion. Sorrel (Acetosella vulgaris) has also been recorded in conservation areas in New South Wales (e.g. Kosciuszko National Park, Cecil Hoskins Nature Reserve and Kuma Nature Reserve) and South Australia (e.g. Montacute Conservation Park, Moana Sands Conservation Park, Totness Recreation Park and Cudlee Creek Conservation Park), and is a weed of disturbed wetlands, woodlands, creeks and granite slopes from Moora to Esperance in south-western Western Australia.
Sorrel (Acetosella vulgaris) leaves contain oxalates and can poison livestock, especially sheep. However, it is generally not grazed by livestock and may become locally dominant in temperate pastures, thus reducing the grazing capacity and productivity of infested areas. It is also a common weed of crops in the temperate regions of Australia.
Sorrel (Acetosella vulgaris) is similar to some of the docks (Rumex spp.), including rambling dock (Acetosa sagittata ) and rosy dock (Acetosa vesicaria ). However, it can generally be distinguished from other docks by the fact that its tiny fruit have no obvious projections (i.e. they lack wings or teeth). The clumping habit of this species and its separate male and female flowers on separate plants are other distinguishing features.
Not declared or considered noxious by any state or territory government in Australia.
Anonymous (2007). Germplasm Resources Information Network (GRIN). http://www.ars-grin.gov/cgi-bin/npgs/html/index.pl. National Germplasm Resources Laboratory, National Genetic Resources Program, Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Beltsville, Maryland, USA.
Anonymous (2007). Weeds Australia. http://www.weeds.org.au. National Weeds Strategy Executive Committee, Launceston, Tasmania.
Auld, B.A. and Medd, R.W. (1996). Weeds: An Illustrated Botanical Guide to Weeds of Australia. Inkata Press, Sydney, New South Wales.
Barker, B., Barker, R., Jessop, J. and Vonow, H. (2005). Census of South Australian Vascular Plants. Fifth Edition. The Botanic Gardens of Adelaide and State Herbarium, Government of South Australia, Adelaide, South Australia.
Blood, K. (2001). Environmental Weeds: a field guide for SE Australia. C.H. Jerram and Associates - Science Publishers, Mt. Waverley, Victoria.
Bostock, P.D. and Holland, A.E. (2007). Census of the Queensland Flora 2007. Queensland Herbarium, Environmental Protection Agency (EPA), Brisbane, Queensland.
Buchanan, A.M. (2007). A Census of the Vascular Plants of Tasmania and Index to The Student s Flora of Tasmania. Web Edition for 2007. http://www.tmag.tas.gov.au/Herbarium/TasVascPlants.pdf. Tasmanian Herbarium, Tasmanian Museum and Art Gallery (TMAG), Hobart, Tasmania.
Carr G.W., Yugovic J.V. and Robinson K.E. (1992). Environmental Weed Invasions in Victoria: conservation and management implications. First Edition. Department of Conservation and Environment, Melbourne, Victoria.
Csurhes, S. and Edwards, R. (1998). Potential Environmental Weeds in Australia: candidate species for preventative control. Environment Australia, Canberra, ACT.
Earl, G., Stelling, F., Titcumb, M. and Berwick, S. (2001). Revegetation Guide for the Goulburn Broken Catchment. Department of Natural Resources and Environment, Victoria.
Hussey, B.M.J., Keighery, G.J., Dodd, J., Lloyd, S.G. and Cousens, R.D. (2007). Western Weeds: a guide to the weeds of Western Australia. Second Edition. The Weed Society of Western Australia, Victoria Park, Western Australia.
Johnston, F.M. (2005). Exotic Plants in the Australian Alps including a Case Study of the Ecology of Achillea millefolium in Kosciuszko National Park. PhD Thesis. Griffith University, Gold Coast, Queensland.
Keighery, G. and Longman, V. (2004). The naturalized vascular plants of Western Australia. 1: checklist, environmental weeds and distribution in IBRA regions. Plant Protection Quarterly 19: 12-32.
Kleinschmidt, H.E., Holland, A. and Simpson, P. (1996). Suburban Weeds. 3rd Edition. Department of Primary Industries, Brisbane, Queensland.
Lepschi, B.J., Adams, L.G., Mallinson, D.J. and Jones, D.L. (2007). Census of the Vascular Plants of the Australian Capital Territory. http://www.anbg.gov.au/cpbr/ACT-census/. Centre for Plant Biodiversity Research, Canberra, ACT.
McDougall, K.L. and Walsh, N.G. (2007). Treeless vegetation of the Australian Alps. Cunninghamia 10: 1-57.
Murphy, A.H. and Downe, J. (2006). National Recovery Plan for the Euroa Guinea-flower Hibbertia humifusa subspecies erigens. Department of Sustainability and Environment (DSE), Melbourne, Victoria.
Navie, S.C., Markwell, B., Playford, J. and Adkins, S.W. (2002). Suburban and Environmental Weeds: an interactive identification and information system. CD-ROM. The University of Queensland, St. Lucia, Brisbane, Queensland.
Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious Weeds of Australia. Inkata Press, Melbourne, Victoria.
Spooner, A., Carpenter, J., Smith, G. and Spence, K. (2007). *Acetosella vulgaris Fourr. FloraBase: The Western Australian Flora. http://florabase.calm.wa.gov.au. Western Australian Herbarium, Department of Conservation and Land Management (CALM), Perth, Western Australia.
Stanley, T.E. and Ross, E.M. (1983). Flora of South-eastern Queensland. Volume 1. Department of Primary Industries, Brisbane, Queensland.
Walsh, N.G. and Stajsic, V. (2007). A Census of the Vascular Plants of Victoria. Eighth Edition. National Herbarium of Victoria, South Yarra, Victoria.
Wilding, J.L., Barnett, A.G. and Amor, R.L. (1986). Crop Weeds. Inkata Press, Melbourne, Victoria.
Wilson, K.L. (2007). Acetosella vulgaris Fourr. New South Wales Flora Online. PlantNET - The Plant Information Network System of Botanic Gardens Trust. http://plantnet.rbgsyd.nsw.gov.au. Royal Botanic Gardens and Domain Trust, Sydney, New South Wales.