The leaves are bipinnate or tripinnate, with a feathery appearance, and green to strongly glaucous blue-green in colour. The flowers are yellow, with 4–5 petals, about 1 cm diameter, and borne in cymes. The fruit is a 4–5 lobed capsule, containing numerous seeds.
It is very bitter. It was used extensively in Middle Eastern cuisine in olden days[when?], as well as in many ancient Roman recipes (according to Apicius), and it is still used in northern Africa. In Italy rue leaves are sometimes added to grappa to obtain grappa alla ruta.
Extracts from rue have been used to treat eyestrain, sore eyes, and as insect repellent.[2] Rue has been used internally as an antispasmodic, as a treatment for menstrual problems, as an abortifacient, and as a sedative.[3]
Precautions
Caution should be taken with using rue topically. Applied to the skin with sun exposure, the oil and leaves can cause blistering.[4] Some people are much more sensitive than others.