Description: Annual of erect stem, up to 30 cm tall. Their colour is gray-blue. The leaves are opposite and oval. The upper ones fused together. The petals are yellow, up to 1.5 cm long. The flowers are collected in loose inflorescences at the tops of the stems. The fruit is a capsule.

Flowering time: May-October

Habitat: Scrubland, dry rocky grasslands

Interesting fact: Yellow color can be produced from a yellow-wort.