[Overview]
An annual, perennial or subshrub.
In Japan it is mainly treated as an annual sown in autumn.
The leaves are simple and opposite.
The flowers are borne singly in the leaf axils or in short racemes at the stem tips.
The corolla is two-lipped, with a 4-lobed upper lip and an entire or 2-lobed lower lip, and a pouch-like swelling or spur develops at the base of the flower.
The fruit is a capsule, and the seeds are winged.
[Cultivation]
Propagate from seed or by stem cuttings.
It prefers a cool climate and dislikes intense heat, cold and excess moisture.
It prefers a sunny location and well-drained soil; in poor light it becomes leggy and falls over.
Protect it from cold wind and frost.
For potted plants, water thoroughly when the soil surface dries; for plants in the ground, rainfall is sufficient.
Pests and diseases include aphids and spider mites.
