Euphorbia sieboldiana var. sieboldiana ("Natsutodai")

Japanese name: ナツトウダイ （夏灯台）
Scientific name: Euphorbia sieboldiana var. sieboldiana

[Overview]
A perennial 15–40 cm tall, found in woods, at woodland edges, and in wetlands.
It has a rhizome.
When the stem or leaves are damaged, a white latex comes out.
The stem is slender and erect.
The leaves are simple and alternate, oblanceolate to ovate, 5–15 cm long and 1–2.5 cm wide.
The leaf margins are entire.
Five leaves are borne in a whorl-like arrangement at the branch tip, and from there 5 flowering branches radiate out.
At the tip of each flowering branch there are 2 triangular bracts, and a cup-shaped inflorescence (cyathium) is produced at their center.
The flowers are enclosed in a yellowish-green, urn-shaped involucre and have no petals.
The fruit is a spherical capsule.

[Uses]
Although it is a poisonous plant, it is used medicinally.

[Cultivation]
Propagate from seed, by division, or by cuttings.
For cuttings, wash off the white latex right away by rinsing the cut end in water or soaking it in water, then let the cut end dry before inserting it.
It prefers sunny, well-ventilated, well-drained soil.
Take care not to let it become too moist when watering; for potted plants, water thoroughly when the soil dries from spring to autumn, and keep it on the dry side in winter.
For plants in the ground, rainfall is sufficient.
It tolerates dryness well.
In spring and autumn, apply a small amount of slow-release fertilizer.
Pests and diseases include rust, powdery mildew and scale insects.

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