An annual hemiparasite, mainly on the roots of grasses. Formerly an arable weed, it now occurs in open grassland beside hedges and ditch-banks, field-borders, in a disused brick-pit and on slumping chalk cliff-faces. Lowland.
Although an archaeophyte in parts of N. Europe, this conspicuous species was not recorded in Britain until 1724. Originally introduced with crop-seed, it has declined due to improved seed cleaning, agricultural intensification and a lack of disturbance at some sites. It was rare by 1930, and has continued to decline since then. It has been deliberately planted at some sites.
M. arvense has a European Temperate distribution, although it is absent from much of W. Europe.
Count of 10km squares in Great Britain: 50
Count of 10km squares in Ireland: 0
Count of 10km squares in the Channel Isles: 0
Atlas Change Index: -0.49
RDB Species Accounts
Melampyrum arvense L. (Scrophulariaceae)
Field cow-wheat, Gliniogai'r Maes
Status in Britain: ENDANGERED. WCA Schedule 8.
Status in Europe: Not threatened.
M. arvense is typically a species of grasslands in which prominent species are Arrhenatherum elatius, Brachypodium pinnatum or Bromopsis erecta. Soils are usually calcareous, and sites in both Britain and mainland Europe are often on field-edges or road verges where there has been recent disturbance and where the grassland has not become too rank. These grasslands can often be relatively species-rich: associates include Festuca rubra, Heracleum sphondylium, Rubus fruticosus and Tussilago farfara, and on the more chalky soils, also Clematis vitalba, Galium mollugo, Helianthemum nummularium, Hippocrepis comosa and Origanum vulgare. One of the British sites is now in a garden sited in the corner of a former arable field. This species was formerly found in arable fields, particularly on the Isle of Wight where it was said to be “so abundant as to render the bread discoloured and unwholesome, the seed being ground up with the wheat” (Townsend 1904), and locally called 'poverty weed'.
This species is an annual hemi-parasitic herb with a wide variety of host plants ranging from Salix alba to cultivated cereals (Oesau 1975). Flowering occurs between June and September, depending on climatic conditions, and bees are the usual pollinators. Its seeds are similar in size and weight to those of cereals, and have poor dispersal characteristics. Up to half the annual seed production may germinate in the following year, while seed may remain dormant in the soil for up to two years (Matthies 1991) or longer (L.Farrell, pers. comm.).
M. arvense was formerly found in a number of sites in southern and eastern England, but was never common except very locally in Norfolk, Essex and the Isle of Wight. It is now known from only four sites, in the Isle of Wight, Wiltshire and Bedfordshire, but with flourishing populations at all sites. In 1996 between 1,000 and 3,000 plants were recorded growing on a chalk cliff-face in the Isle of Wight. It has been recorded from ten other sites since 1940, although at most of these it has not persisted for long (Wilson 1993).
As an annual species it is intolerant of both strong competition and heavy grazing. At one site the open conditions are preserved by natural erosion, but at the other three only by human intervention, so that natural succession is a potential threat if conservation management is discontinued. Populations in Bedfordshire and the Isle of Wight were much reduced when the surrounding vegetation was allowed to become rank, but numbers have recovered following conservation management. More efficient seed cleaning, and agricultural intensification, including the greater use of herbicides, have led to the disappearance of M. arvense from arable fields (Wilson 1993).
In Europe, its range extends eastwards to the Urals, as far north as southern Sweden and southwards to the northern Mediterranean (Matthies 1991). It has declined in recent years over the whole of western Europe, although it is still widespread in eastern Europe.
P. J. Wilson
PLANTATT - Attributes of British and Irish plants. (.zip 1455KB) This dataset was compiled and published in 2004, and last updated in November 2008. Download includes an Excel spreadsheet of the attributes, and a PDF explaining the background and nomenclature. Note that the PDF version is the booklet as published, whereas the Excel spreadsheet incorporates subsequent corrections. A hardcopy can be purchased from the Centre for Ecology and Hydrology.