Information on Lesser Trefoil

Common Name: Lesser Trefoil
Scientific Name: Trifolium dubium
Irish Name: Seamar bhuí
Family Group: Fabaceae
Distribution: View Map (Courtesy of the BSBI)
Flowering Period


Click for list of all flowering by month
Lesser Trefoil could sometimes be confused with:

Medick, Black, Trefoil, Hop,

Also known as Yellow Clover, this is a low-growing, mat-forming, hairless annual which has between 5 and 20 yellow peaflowers in compact little flowerheads 8-9mm across. The trifoliate oval leaves are slightly notched, and not pointed, the terminal leaf being short-stalked. Lesser Trefoil flowers from May to October and can be found growing in dry, grassy places and wasteland.  In autumn, the flowers turn brown and droop hiding the tiny straight pods. It is native plant belonging to the family Fabaceae. 

I first identified this wildflower in 1978 at Kilcoole, Co Wicklow and photographed it at Ballyteigue, Co Wexford in 2008 

If you are satisfied you have correctly identified this plant, please submit your sighting to the National Biodiversity Data Centre

Trefoil, Lesser
Trefoil, Lesser

Clovers and other peaflowers help to supplement nitrogen supplies to the soil by fixing nitrogen from the atmosphere. They do this by means of the nitrogen-fixing bacteria which live on nodules on the plant roots.  Compost made from the residue of such plants also forms a useful addition to the soil.  Without nitrogen an estimated one-third of our current agricultural production would be lost.