Japanese name: クガイソウ（九蓋草、九階草） Scientific name:Veronicastrum japonicum var. japonicum
[Overview]
A perennial 0.8–2 m tall, found in sunny grasslands in the mountains.
The stem is erect and unbranched.
The leaves are simple, in whorls of 4–10, elliptical, 5–20 cm long and 2–5 cm wide, with a long pointed tip.
The leaf margin has sharp teeth.
Long racemes from the stem tip and from the upper leaf axils bear dense flowers.
The flowers are pale purple, 0.5–0.6 cm long, and the 2 stamens project far out of the flower.
The fruit is an ovate capsule 2.5 mm long.
[Uses]
The roots and rhizomes are used medicinally.
[Cultivation]
Propagate from seed, by division, or by cuttings.
It prefers full sun to bright partial shade and well-drained, fertile soil.
It dislikes strong dryness.
For potted plants, water thoroughly when the soil surface dries; for plants in the ground, rainfall is sufficient unless summer brings a long spell of sunny weather and the soil becomes severely dry.
In spring and autumn, apply slow-release fertilizer placed on the soil.
There are no particular pests or diseases.
[Notes]
The Japanese name comes from the way the leaves grow in layers.
