Isodon trichocarpus ("Kurobanahikiokoshi")

Japanese name: クロバナヒキオコシ （黒花引起）
Scientific name: Isodon trichocarpus

[Overview]
A perennial 50–150 cm tall, found at forest edges, riverbeds and similar places in the mountains.
The stem has downward-pointing hairs and is square in cross-section.
Leaves are simple and opposite, triangular-broadly ovate, 6–15 cm long and 3–7.5 cm wide.
The upper surface of the leaf has sparse hairs, and the veins on the underside have short hairs and glandular dots.
The leaf margin has serrations.
The petiole is winged.
Many cymes arise from the leaf axils and stem tips, forming a conical flower spike as a whole.
The flowers are blackish purple, two-lipped, 0.5–0.6 cm long.
The fruit consists of four nutlets.

[Uses]
The whole plant is used medicinally.

[Cultivation]
Propagate by division.
It prefers a sunny to partially shaded position and fertile, well-drained soil.
For planting in the ground, it is best planted under deciduous trees.
For potted plants, from spring to autumn water thoroughly when the soil surface dries; in winter, water so that the soil does not dry out completely, or leave the pot where it will be rained on.
For plants in the ground, rainfall is sufficient.
From spring to autumn, apply slow-release fertilizer placed on the soil.
Cutting it back short in early summer produces side shoots and increases the number of flowers.
There are no particular pests or diseases.

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