Leucanthemum vulgare
(oxeye daisy)

L. vulgare is a perennial native to Europe and western Asia which has been introduced widely around the world. This species is reported as being invasive in the USA, Canada, India, New Zealand and Australia. In pastures and meadows it can form dense stands which can outcompete native flora and may reduce the diversity of natural vegetation or pasture quality. L. vulgare produces a large number of seed and can also regenerate from fragments of rhizome which makes control of this species difficult. L. vulgare may also serve as a host and reservoir for several species of polyphagous gall forming Meloidogyne nematodes. L. vulgare is federally regulated as a primary noxious weed in Canada.

L. vulgare is native to Europe and eastwards into central Asia. L. vulgare has been introduced to many other temperate areas including further east in Asia and particularly in North America. It now occurs sporadically in subtropical regions including Australia, South America and South Africa and in more tropical countries in East Africa but mainly at high elevations. In the USA, USDA-ARS (2015) indicates extensive but incomplete distribution across continental USA. The USDA-NRCS (2015) however indicates every state to be invaded including Alaska and, further afield, Hawaii. The distribution table shows mainly where it is native or has naturalized. It is however, widely cultivated and may be present in a number of further territories.

L. vulgare is a plant of disturbed areas such as roadsides, waste areas and overgrazed or infertile grassland. It can benefit from high moisture and high levels of nutrients but under these conditions it suffers competition from taller plants. As a result it is more likely to be dominant under less fertile conditions. It has been noted that native soils have a strong suppressive potential towards L. vulgare, whereas this is not the case in soils from across the introduced range (Maron et al., 2014).

A range of crops may be invaded by L. vulgare including barley (Hordeum vulgare), flax (Linum usitatissimum), oats (Avena sativa), oilseed rape (Brassica napus), sunflower (Helianthus annuus), wheat (Triticum species) and Lucerne (Medicago sativa), but it is most commonly a problem in pastures. In natural grassland it may become dominant to the detriment of the natural vegetation, but no individual species have been reportedly threatened.

Genetics

The diploid (2n = 18) L. vulgare is part of a species complex (L. vulgare aggregate). It is closely related with the tetraploid L .ircutianum (2n = 36). The two species differ slightly in morphology with most parts, including pollen, being larger in the tetraploid. There are also small differences in flowering time and habitat preference. Both species are widely distributed across Europe. According to Mulligan (1958) the diploid is most common across North America. Both the diploid L. vulgare and the tetraploid L. ircutianum occur in Canada with L. ircutianum mainly found in the east of the country (Clements et al., 2004).

Reproductive Biology

Andersson (2008) reports that L. vulgare is self-incompatible and it has been shown that the white ray florets play a significant role in attracting pollinating insects. However, Clements et al. (2004) indicate that, although it is chiefly insect pollinated, self pollination can later result from stigmas bending to make contact with the anthers. Insects involved in pollination include bumble bees and a range of other small insects but not honey bees. Seed production can approach 300 seeds per inflorescence and 10,000 per m² (Parsons and Cuthbertson, 1992).

Seeds are viable as soon as they are shed and show little or no dormancy. When first shed they require light for germination but after stratification they are less dependent on light. Pêgo et al. (2012) found temperatures of 25°C to be optimal for germination, while high temperatures of 30°C were damaging.

Vegetative reproduction can also occur from rhizome fragments after cultivation.

Physiology and Phenology

Germination may occur in the autumn after shedding or in the following spring. A rosette is formed initially and this may produce some flowering shoots in the first year but mostly they occur in subsequent years. Flowering is triggered by a combination of low temperature vernalization and long days. Plants flower from around May to July. Seeds may mature within ten days of flowering. After seed shedding in autumn the shoots die down leaving the rosette to overwinter.

As the plant matures, it develops a spreading rootstock and short rhizomes from which further shoots can occur. In the absence of competition a single plant can spread to produce 75 flowering shoots and nearly 400 inflorescences in two years. Several inflorescences develop per stem, but a single flower head is more usual under more competitive conditions.

Longevity

In the absence of dormancy the longevity of the seeds may be quite short in particular when conditions are suitable for germination. However, in a study by Toole and Brown (1946) seeds buried deeply in the soil in 1902 retained up to 40% viability over a period of 10 years. This decreased significantly over 20 years but after 39 years 1% viability was still recorded. Established plants of L. vulgare vary in their ability to persist. Böcher and Larsen (1967) found that diploid plants tended not to survive much beyond two years, whereas the tetraploids were more genuinely perennial.

Nutrition

In a grassland situation, L. vulgare benefited from the addition of slurry but not from potassium and phosphorus (Korevaar, 2013). On its own, it benefited from nitrogen fertilization but in a mixed sward, competing species benefited to a greater extent (Palmborg et al., 2004). Hence L. vulgare is more likely to thrive in relatively infertile soils.

Associations

L. vulgare is associated with arbuscular mycorrhizal fungi some of which provide protection against the pathogen Rhizoctonia solani [Thanatephorus cucumeris] (Lewandowski et al., 2013).

Environmental Requirements

L. vulgare is moderately salt and drought tolerant, as suggested by the slightly fleshy leaves (Guan et al., 2010). It is also moderately tolerant of frost (USDA hardiness zones: 3-9), and shading. An 85% reduction in light was seen to reduce rosette biomass by 70% and seedling biomass by 92% (Clements et al., 2004). In the UK, it is found to prefer neutral to basic soils over acid soils (Howarth and Williams, 1968). Seed production was seen to increase under raised levels of carbon dioxide (Rüegg et al., 1999).

A wide range of natural enemies including insects, fungi, viruses and bacteria have all been recorded from L. vulgare and can be found in full detail in Clements et al. (2004).

A number of these, Dichrorampha aeratana, D. consortana, D. baixerasana, Cyphocleonus trisulcatus, Tephritis neesii and Apion stolidum [Diplapion stolidum] are currently being studied for their potential as biological control agents (McClay et al., 2013).

Animal feed, fodder, forage

• pesticide, pest repellent

Environmental

• Amenity
• Landscape improvement
• Wildlife habitat

General

• Ornamental
• Sociocultural value

Medicinal, pharmaceutical

• Source of medicine/pharmaceutical
• Traditional/folklore

Ornamental

• Cut flower

There are superficial similarities to a number of other Asteraceae with conspicuous white flowers but the majority have very different foliage. A likely confusion may occur with the cultivated Shasta daisy, L. x superbum, a hybrid of which L. vulgare is a possible parent along with L. maximum and L. lacustre. The Shasta daisy is taller and has larger flowers than L. vulgare and there is a brown membranous margin toward the apex of each floral bract, while the floral bracts of L. vulgare are brown along the entire length of their margins.

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Prevention

SPS Measures

L. vulgare is a provincially regulated as a weed in Alberta and federally regulated as a primary noxious weed by the Seeds Act (Canadian Council on Invasive Species, 2016). It is also a prohibited weed in Victoria, Australia (Weeds of Queensland, 2015).

Control

Cultural Control and Sanitary Measures

In Canada, Booth and Skelton (2009) found that feeding by goats (Capra aegagrus) could provide control equivalent to that provided by the use of herbicides over a five year period. Given the susceptibility of L. vulgare to shading, the use of fertilizers can be a very effective means of suppression, often at least equal to that from herbicides, via the increased growth of competing vegetation (Clements et al., 2004). It also has the advantage of enhancing any forage species and avoiding the damage that may be done to them by most herbicides.

Physical/Mechanical Control

Seedlings and established plants are readily destroyed by cultivation, but this may not be feasible without damaging associated pasture plants and it may also result in the stimulation of new germination and rapid re-establishment of L. vulgare. In Montana, regular mowing of grassland infested with L. vulgare has also been suggested to be effective to reduce seed production (Mangold et al., 2009). However, in Alberta it has been found that mowing can increase the density of L. vulgare and in an experimental one-year study a positive correlation between the number of mowings per year and the number of L. vulgare plants in the following year has been found (Clements et al., 2004).

Biological Control

Based on literature surveys eight European species have been prioritized as potential biological control agents based on records of their restricted host range. These include the root-mining tortricid moths Dichrorampha aeratana and D. baixerasana, the shoot-mining Dichrorampha consortana, the root-feeding weevils Cyphocleonus trisulcatus and Diplapion stolidum, the root-galling fly Oxyna nebulosa, the flowerhead-attacking tephritid fly Tephritis neesii and the flowerhead-attacking weevil Microplontus campestris (McClay et al., 2013). From 2010 onwards, host-specificity tests have been conducted to investigate the host range of these potential biological control agents. Tests with D. stolidum and C. trisulcatus revealed that these species are not specific enough to be considered further. In addition, tests with M. campestris revealed that this species has no evident impact on seed output. Host-specificity tests with D. aeratana and O. nebulosa are ongoing. and to date, none of these potential agents have been introduced to North America.

Chemical Control

L. vulgare is not readily controlled by herbicides that are safe to use in mixed pasture or wild vegetation. 2,4-D, mecoprop and MCPA are only effective in relatively high doses and may require a mixture with metsulfuron, picloram, dicamba, tribenuron, bentazon, clopyralid or thifensulfuron. The latter three are among the more selective in legumes. Glyphosate is effective but non-selective. Martin et al. (1990) however report the successful use of a weed wiper to apply glyphosate, metsulfuron, picloram and 2,4-D, 2,4-D and clopyralid. Where associated leguminous or other herbs are damaged, the reduced competition leads to all the more rapid recovery of L. vulgare. More detail can be found in Clements et al. (2004).

19/10/2016 Updated by:

Sonja Stutz, CABI, Switzerland

25/03/2015 Original text by:

Chris Parker, Consultant, Bristol, UK