Achillea alpina subsp. alpina var. longiligulata (alpine yarrow, "Nokogiriso")

Japanese name: ノコギリソウ （鋸草）
Scientific name: Achillea alpina subsp. alpina var. longiligulata

[Overview]
A perennial 50–100 cm tall, found in sunny grasslands in the mountains.
It spreads by underground stems and grows thickly.
The leaves are alternate, 6–10 cm long and 0.7–1.5 cm wide, finely divided like the teeth of a comb, with sharp serrations on the margin.
Corymb-like inflorescences at the stem tips bear many small white to pale pink flower heads densely.
Each flower head has 5–7 ray florets.
The fruit is an achene.

[Uses]
The whole plant has tonic and stomachic effects.
The young shoots are edible.

[Cultivation]
Propagate from seed, by division, or by shoot cuttings.
It prefers a sunny, well-drained site.
It is hardy and spreads by underground stems, so when planted in a garden it is better to make a frame underground to keep it from spreading too much.
For potted plants, water when the soil surface dries.
Fertilizer is not particularly necessary.
It dislikes heat and humidity, so keep it well ventilated.
Pests and diseases include aphids, powdery mildew and gray mold.
When the branches become crowded, they can become stuffy and disease may develop.

[Notes]
The Japanese name likens the shape of the leaves to a saw.

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