Japanese name: ヘンルーダ Scientific name:Ruta graveolens
[Overview]
An evergreen perennial 0.5–1 m tall.
The whole plant is tinged with grayish green and has a strong fragrance.
Leaves are alternate and twice pinnately divided, with elliptic to obovate lobes and entire margins.
Corymbs or cymes at the branch tips bear yellow four-petaled flowers 1.5–2 cm across.
The petals have fine serrations.
The fruit is a capsule.
[History]
It was introduced to Japan around the time of the Meiji Restoration.
[Uses]
It is used medicinally.
It was formerly eaten as well, but it was found to be toxic, and it is now hardly used.
Touching the sap of the stems and leaves causes a rash.
[Cultivation]
Propagate from seed, by division, or by cuttings.
Care is needed because touching the sap of the stems and leaves causes a rash.
It can overwinter outdoors in areas without frost.
It prefers fertile, dry, sunny, well-drained soil.
Cultivation is easy.
Take care not to overwater; for potted plants, water thoroughly after the soil dries, and for plants in the ground, rainfall is sufficient.
From spring to autumn, place slow-release fertilizer on the soil.
Root rot can occur.
Also, take care because the larvae of swallowtail butterflies eat the plant.
[Notes]
The name henruda comes from Dutch.
It is a food plant of the larvae of swallowtail butterflies.
