Datura metel (downy thorn apple, "Chosen'asagao")

Japanese name: チョウセンアサガオ （朝鮮朝顔）
Scientific name: Datura metel

[Overview]
An annual 1–1.5 m tall, cultivated for ornament or medicine.
In warm regions it becomes a perennial.
The whole plant is hairless or sparsely hairy.
The new shoots, stems and leaves are sometimes tinged with purple.
It has thick roots.
The stem branches frequently.
Leaves are simple and alternate, ovate to broadly ovate, 10–20 cm long and about 10 cm wide.
The leaf margin is entire or has large, irregular teeth.
The flowers are solitary in the leaf axils and open upward; they are white, large and trumpet-shaped, 15–20 cm across and 14–20 cm long.
The tip of the corolla is 5-lobed, and the lobe tips are sharply pointed like horns.
The calyx is tubular, 4–9 cm long.
The fruit is a spherical capsule about 3 cm across, with thick spines on the surface, and it splits open when ripe.

[History]
It came to Japan in 1684 via China as a medicinal herb.

[Uses]
The whole plant is extremely poisonous, and the seeds and dried leaves are used medicinally.
In 1805 the physician Seishu Hanaoka used Chosen-asagao to perform general anesthesia for breast cancer surgery.

[Cultivation]
Propagate from seed.
It prefers a sunny, well-drained site and is not particular about soil.
Rainfall is sufficient for watering.
A lack of fertilizer reduces flowering, so in addition to a base fertilizer, place slow-release fertilizer on the soil once a month.
There are no particular pests or diseases.

[Notes]
Poisoning accidents have occurred from mistaking the roots for burdock and the buds for okra and eating them.
Poisoning accidents have also occurred with eggplants grown on Chosen-asagao rootstock.

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