The source plant, Anthemis cotula (stinking mayweed
, dog fennel) acts as a skin sensitizer in some individuals and this action has been attributed to anthecotulide (1) (Hausen et al.
Chickweeds, orache, spurge, cress, dead-nettle, pineapple weed, mayweed
, ragweed, Shepherd's purse, hawkweed, chamomile, and speedwell are just a few of the annual weeds prepared to add massive amounts of seed to those already in the soil seed bank.
Dried dandelion leaves, as well as mayweed
, goutweed, Canada mayflower, and clammy everlasting, leave much to be desired.
Dandelions are perhaps the commonest but groundsel, pineapple weed, mayweed
, thistles, ragwort, yarrow and coltsfoot can annoy us just as easily.
The next most frequent broad-leaved weeds identified by farmers were mayweed
(infesting 86pc of winter wheat), chickweed (infesting 82pc of the crop), charlock (75pc of the total crop), common field speedwell (69pc), fat hen (68pc), volunteer oilseed rape (68pc), field pansy (65pc) common poppy (60pc), knotgrass (59pc) and groundsel (58pc).