• Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

Five common species of Malva are found in New Zealand. These are:

Dwarf mallow (Malva neglecta)

  • A short-lived perennial herb which is sometimes prostate or can be more upright, with hairy stems and leaves, especially the lower surfaces
  • Leaves are kidney-shaped or round, up to 7 cm across with 5-7 shallow lobes. Flowers are in clusters of 2-5, with white to lilac petals, often with lilac or pink veins, and are 8-15 mm long
  • Fruiting body contains 12-15 mericarps, each of which has a smooth back, is sharply angled, and is usually covered in hairs
  • Found throughout the North Island and in eastern areas of the South Island, in waste places, pasture, cultivated land and riverbeds.

French mallow (Malva nicaeensis)

  • This species is very similar to dwarf mallow but its mericarps are rough, often hairless at maturity and the flowers may be slightly darker
  • Occurs throughout the North Island and in Nelson, Marlborough, Canterbury and Otago, in waste places, often near the sea.

Large-flowered mallow (Malva sylvestris)

  • Is more erect, up to 120 cm tall, with conspicuous flowers about 4 cm across, usually with red-veined pink petals
  • Flowers are in clusters of 2 to 10 in the axils of leaves
  • Each flower has 5 deeply-notched petals, two to five times longer than the calyx
  • Fruit are flat, disc-shaped, brownish green, with 8-12 segments which are strongly veined on the back and have sharp angles
  • Leaves are round or kidney-shaped, up to 15 cm in diameter, on long stalks
  • Leaves are usually 5-lobed with shallow lobes when young and becoming more deeply lobed and often folded along the main veins when older
  • Occurs throughout the North Island except for Taranaki, but is more common in parts of the Waikato, Poverty Bay and Hawkes Bay
  • Occasionally occurs in Nelson, Marlborough, Canterbury, Otago, and the Chatham Islands, especially on bare ground on sheep camps, yards, near trees and in gateways.

Small-flowered mallow (Malva parviflora)

  • A semi-erect plant up to 50 cm tall with almost round leaves up to 8 cm across and flowers that are pale mauve or whitish, in clusters of 2-5
  • The five, small white to pale lilac petals are only just longer than the green sepals
  • Malva parviflora fruit are round, with about 10 net-veined segments with slightly winged margins
  • Probably the most common mallow species in New Zealand
  • Found on waste land, and on bare ground, such as on sheep camps, yards, near trees and in gateways, throughout the NI and SI (except for Westland and Fiordland).

Tree mallow (Malva dendromorpha)

  • This species is a much larger plant, growing up to 2 m tall when flowering, conspicuous when growing on roadsides
  • Also has distinctive large lilac or deep-pink flowers with purple or red veins and a dark centre, up to 4 cm across
  • Flower stalks are tall and woody
  • Found throughout New Zealand in waste places, roadsides, coastal sites and on cultivated land. A variegated variety is often found in older gardens and in waste places.

Creeping mallow (Modiola caroliniana)

  • Related to the other mallows
  • Mat-forming annual, biennial or perennial with creeping stems that root at the nodes and can be up to 1 m long
  • Light green leaves are usually, but not always, circular in outline, about 4 cm across
  • Flowers are solitary, with red or orange-red petals, on stalks 1-5 cm long
  • Leaves of young plants are shallowly lobed; on older plants they are often divided into 3-7 lobes
  • Fruits are disc-shaped, about 1 cm across, with 15-25 segments, each containing two or three seeds.

Origin

  • Species of Malva originally came from Europe and some were also found in North Africa
  • Creeping mallow (Modiola caroliniana) originated in tropical America and warm temperate North America.

Life cycle

  • Small-flowered mallow (Malva parviflora) is described as an annual, completing its life cycle from germination to setting seed within one year
  • Most of the other species: creeping mallow, Modiola caroliniana; dwarf mallow, Malva neglecta; French mallow, Malva nicaeensis; large-flowered mallow, Malva sylvestris, are usually perennials but, if conditions for growth are not favourable, they can complete their life cycles in a shorter time
  • Tree mallow (Malva dendromorpha) is regarded as a biennial species.

Benefits

  • Leaves of some of these species have been used uncooked in salads or cooked as ‘greens’ in some parts of the world
  • Plant extracts are claimed to be astringent, laxative and to alleviate skin inflammation.

Impact on pasture

  • These species can take up pasture space which could be better used by more productive and useful grasses and clovers.

Impact on forage crops

  • All the Malva spp. except tree mallow can be persistent and difficult to control weeds in annual crops.

Impact on livestock

  • Small-flowered mallow (Malva parviflora) has often caused staggers in sheep (and less often in cattle and horses) in Australia and, to a lesser extent in South Africa, but no cases have been confirmed here
  • Creeping mallow (Modiola caroliniana) has been suspected of causing staggers in sheep in Australia and of livestock in North America but there are no records of it causing problems here.

Grazing management

  • Good pasture management, using appropriate pasture species, a good fertiliser regime and good grazing management are the best ways of solving problems of mallow invasion
  • If a pasture is already heavily infested pasture renewal may be the most appropriate way of solving the problem.

Chemical control (taken, with minor modifications, from Harrington, 2017)

  • No selective herbicides can be guaranteed to remove mallow from pasture, although flumetsulam should kill young seedlings and MCPA can give some control of younger plants
  • If mallows only occur in patches in the pasture, spot spraying with a 2,4-D/dicamba mixture may give good control although both these will kill clovers and may remain active in the soil for some time
  • In establishing lucerne, mallow seedlings can be killed with flumetsulam
  • Imazethapyr is recommended to control mallows in lucerne
  • In orchards, glyphosate and amitrole are not very effective for controlling mallows and their repeated use can result in mallows dominating the vegetation. The best idea is to add oxyfluorfen, carfentrazone or fluroxypyr to glyphosate to improve its performance (note that fluroxypyr is only registered for use in apple orchards).

Connor HE 1977. The poisonous plants in New Zealand. GP Publications Ltd., Wellington, New Zealand. DSIR Bulletin 99. 247 p.

Harrington, KE 2017. Mallow (Malva spp.). Massey University Weeds Database (accessed 2 May 2017)

Popay I, Champion P, James T 2010. An illustrated guide to common weeds of New Zealand. 3rd edition. New Zealand Plant Protection Society, Christchurch, New Zealand. 416 p.