Information on Yellow-wort

Common Name: Yellow-wort
Scientific Name: Blackstonia perfoliata
Irish Name: Dréimire buí
Family Group: Gentianaceae
Distribution: View Map (Courtesy of the BSBI)
Flowering Period

Click for list of all flowering by month
Yellow-wort is not easily confused with other wild plants on this web site.

Dréimire buí … yellow ladder .. a most appropriate name for this little plant which seems to have little steps up its stems.  Perfoliata .. through-leaved .. referring to the leaves which are fused together at the base with the stem threading its way through.  This delightful plant is quite unmistakeable, with those distinctive ovate, rubbery leaves joined together to form a sort of boat-shaped saucer, grey-green in colour.  The pretty little yellow flowers (10-15mm) only open their six to eight petals in sunshine from June to October and are borne in loose terminal clusters.  This is to a large extent a flower of the Burren and the Aran Islands, although there are other locations in Ireland where it grows.  It favours sandhills, rocky places and calcareous grasslands.  It is a native plant and belongs to the family Gentianaceae.    

I first identified this flower at Black Head, Co Clare in 1979 and photographed it in the same area in 2005. 

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

Blackstonia perfoliata is named after the apothecary and botanist, John Blackstone (1712–1753).  Blackstone worked in London and spent his holidays at Harefield, north Middlesex.  His major work was Fasciculus Plantarum circa Harefield sponte nascentium. Cum Appendice, ad Loci Historiam spectante which catalogued plants he found in Harefield and included the precise location of the rarer plants.  He was working on a second work when he died prematurely aged 41.