Yellow-wort
Blackstonia perfoliata
Family · Gentianaceae · Harmless
The yellow flower on a bluish plant, recognised without hesitation by one unique detail: the leaves fuse in pairs around the stem, which seems to pierce them through the middle.
Fields and pasture · Streams and ditches · Dunes and sand · Roadsides and waste ground
Also known asyellow centaury
How to tell it
A smooth bluish plant, without a single hair. The stem leaves are opposite and fused to each other at the base, forming a continuous plate the stem passes through, which no other yellow plant in the Peninsula does. Bright yellow flowers with six to twelve narrow petals, opening only in strong sun.
What it is confused with
No dangerous lookalikes known in the Iberian Peninsula.
What it is for
Traditional medicinal use as a digestive bitter, like the other gentian relatives. Traditional use, in the past. It indicates limestone soil wet in winter and dry in summer, a ground type that hosts many orchids.