Pineapple Mayweed is common throughout the UK and Ireland. It is a native of Asia and is thought to arrived in the UK via America.
This low-growing annual has a strong pineapple scent - hence its common name, also sometimes abbreviated to pineappleweed. It is very much a weed of cultivated soil, often growing in dense mats in the well trodden areas around farm gates. It seems that its seeds are carried either in the treads of shoes and boots, or in tyre treads. This may account for its extensive colonisation of track and roadsides.
The flowers, which have no outer florets, appear in May, but this flower can be seen blooming in Wales on into November. We photographed this specimen on the banks of the River Teifi, in West Wales.