Small-flowered Mallow

Malva parviflora L.

Family: - Malvaceae.

Names:

Malva is from the Greek malache meaning soft and refers to the relaxing nature of these plants.
Parviflora is from the Greek parvus meaning small and floris meaning flower referring to the small flower petals of this species.
Small-flowered Mallow because the petals in this species are smaller than in others.

Other names:

Mallows
Marshmallow
Ringleaf Marshmallow
Whorled Mallow
Whorlflower Mallow

Summary:

An erect or sprawling, annual or biennial herb to 1.5 metres with round lobed leaves, heart shaped cotyledons, small, 5-petalled white or pink flowers from April to November that swell into 10 mm fruits that look like tiny pumpkins.

Description:

Cotyledons:

Two. Blade 5-8 mm, heart shaped. Tip pointed to somewhat rounded. Base indented. Edges smooth. Petiole 12-18 mm. Hairless. Pale, obvious veins. The seedling has a hypocotyl but no epicotyl.

First leaves:

The first leaves grow singly and are round to oval, 4-8 mm in diameter with a lobed and undulating margin. Prominent veins. The petiole is 7-15 mm long. They form a rosette like clump. Star and simple hairs are on the blade and star hairs only on the petiole.

Leaves:

Alternate.
Stipules -
Petiole - 40-150 mm long, stiff with star and long simple hairs that are often only on the upper surface.
Blade - Dull dark green, round to kidney shaped in outline, 20-70 mm long by 40-120 mm wide with 5-7 finger like lobes with evenly scalloped edges and radiating veins that are prominent of the lower surface. Often pleated between the veins. Notched at the base where the petiole joins. A few, stiff simple hairs and also some twin and star shaped hairs.

Stems:

Erect, bushy or prostrate and spreading, up to 1500 mm, round, solid or may have a small hollow, fibrous, often reddish near base and on the top side, often woody at the base. Branch from the base and along their length. A few, stiff simple hairs and also some twin and star shaped hairs and tubercles (warts) are present.

Flower head:

Clusters of 2-5 flowers on stalks in leaf axils.

Flowers:

Pink, white, or occasionally pale purple, 5-6 mm diameter, bisexual.
Bracts - 3 parallel sided bracteoles attached to the base of the calyx.
Ovary - 8-12 celled. Styles separate into thread like branches that are stigmatic on the inside.
Calyx - Cup shaped, 3-3.5 mm long with ribs between the 5, acute tipped, broadly egg shaped lobes, that are 2-3 mm long and enlarge to 13-15 mm diameter at maturity and spread outwards to expose the fruit. Sparse star hairs and tiny hairs.
Petals - 5, pink, white or occasionally pale lilac, clawed petals, 3-5 mm long, scarcely longer than the calyx. Petal claws are hairless.
Stamens - Staminal tube divided into numerous filaments.
Anthers -

Fruit:

Round, button or pumpkin like capsules, 4-9 mm diameter composed of 8-12, wedge or kidney shaped fruitlets in a ring. Deeply, crosswise wrinkled on the back. Forms 8-12 radiating, almost winged, ridges that extend to make the edge wavy. Hairless, finely hairy or hairless. One seed in each fruitlet. Capsules breaks into individual fruitlets.

Seeds:

Small 1-2 mm wide. Red brown, smooth, kidney shaped, rounded on the back. Surface may have frosted appearance. Often enclosed in a wrinkled or ribbed cream to brown seed coat. Tip round or wrinkled. Edges smooth or winkled. Surface smooth or wrinkled. Up to 5000 seeds per plant.

Roots:

Single taproot.

Key Characters:

Less than 1500 mm tall. Bracteoles linear. Petals scarcely exceeding the calyx.

Biology:

Life cycle:

Annual or biennial. Germinates in spring to autumn and grows rapidly. Flowers August-December. Spring germinating plants may flower when only a few centimetres high and survive over summer to become biennial.

Physiology:

Reproduction:

By seed. Self fertilising.

Flowering times:

April to November in SA.
Spring and early summer in WA.
August to October in Perth.

Seed Biology and Germination:

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed. Seed moves along water ways.
Seed passes through monogastric animals. 700 viable seeds/day have passed through horses. Work is being conducted by P. Michael on the effects of ruminants on seed dispersal. Field observations indicate that sheep are important in dispersal.

Origin and History:

Mediterranean. South Western Europe.

Distribution:

ACT, NSW, NT, QLD, SA, TAS, VIC, WA.
Occurs throughout Tasmania.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate. Mediterranean. Sub tropical.

Soil:

Most soil types. Alluvial flats.

Plant Associations:

Significance:

Beneficial:

Palatable fodder.
Medicinal herb used by South African natives for tapeworm.
Does not host Root Lesion Nematode (Pratylenchus thornei) (63).

Detrimental:

Weed of stock yards, crops, vegetables, pastures, gardens, roadsides, waterways and disturbed areas.
Difficult to control with herbicides.
May reduce Wheat grain yields by up to 30%.
May cause staggers in stock that graze significant quantities.
When poultry feed on the seed or leaves, the whites of eggs may be tinged with pink and the yolks become pasty.
It is a poor host of Root Lesion Nematodes (Pratylenchus neglectus) allowing some build up of numbers (63).

Toxicity:

Sheep, especially lambs are more susceptible than cattle or horses to poisoning. Most cases occur in the July to October period with some as late as December when Mallow has made up a large part of their diet for days or weeks. Toxicity may be passed to lambs through milk.
May contain toxic quantities of nitrate.

Symptoms:

Symptoms usually appear and after driving some distance and include staggers, sluggish movement, stiff action in the hind legs that are tucked under the body, back arched, head stretched forward, knuckling over of the front legs, sitting with the head turned into the body then lying on one side, trembling, rapid breathing and pulse. If forced to move again they often die, otherwise they rest and recover. Symptoms usually appear a day or two after eating Mallows.

Treatment:

Gently remove stock from the infestation. Most stock will recover if left unstressed.
Avoid holding stock in Mallow infested yards.

Legislation:

None.

Management and Control:

Tends to increase as soil fertility increases. Canadian research has shown that banding of fertilisers below the crop seed can reduce the mallow infestation.
Tends to be more prevalent in reduced tillage cropping systems.
Farming systems that include cultivation, grazing, long rotations, banding of fertilisers, early spraying, and the use oxyfluorfen (Goal), diflufenican (Brodal), metribuzin (Lexone or Sencor), triasulfuron (Logran) and to a lesser extent Spray.Seed will keep Mallows at low levels.

Thresholds:

Eradication strategies:

Control patches and infestations around stock yards and camps with 1 L/ha Goal CT. Apply when the as soon as possible after the 2 leaf stage of the Mallows when they are not stressed. This will give some residual control of later emerging Mallows. Repeat the application when necessary. In pasture paddocks keep the level of grazing as high as possible, especially in spring to prevent seed set. Use Tigrex as a Spray Graze in clover based pastures. Use Logran for weed control in wheat. Use Tigrex or Logran for post emergent broadleaf weed control in cereals. Use Brodal or Lexone in Grain Legumes.

Herbicide resistance:

None reported.

Biological Control:

Vegetable weevil often decimates dense stands.

Related plants:

Dwarf Mallow (Malva neglecta)
Mallow-of-Nice (Malva nicaeensis) has purple flowers.
Musk Mallow (Malva moschata)
Tall Mallow (Malva sylvestris) has larger flowers and fewer star hairs on the stems and leaves.

Plants of similar appearance:

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P185. Diagrams. Photo.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P555. Diagram.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P254. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P482. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P517-520. Diagram.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P138.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P176. Photo.

Hyde-Wyatt, B.H. and Morris, D.I. (1975). Tasmanian weed handbook. (Tasmanian Department of Agriculture, Hobart, Tasmania). P92-93. Diagrams.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #795.4.

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P146.

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P100. Diagram.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P106. Diagrams. Photos.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.