Mirabilis jalapa (four o'clock flower, "Oshiroibana")

Japanese name: オシロイバナ （白粉花）
Scientific name: Mirabilis jalapa

[Overview]
A perennial about 1 m tall.
Branches emerge from the leaf axils and spread sideways.
Leaves are simple and opposite, triangular-ovate and entire.
They have leaf stalks.
The flowers gather at the branch tips, borne in cyme-like clusters mixed with leaves.
The bract is cup-shaped and encloses a single flower.
The flower has a tube about 5 cm long and opens widely at the tip to about 3 cm across, but it has no petals; the part that looks like petals is the calyx.
Flower colors are varied, including purplish red, orange, yellow and white, and there are streaked and variegated forms; some plants bear flowers of a different color on each flower.
The flowers open in the evening and wilt the next morning.
The fruit is oval and ripens to black, with wart-like projections on the surface.
The endosperm is white and powdery.

[History]
It is recorded in the Genroku era of the Edo period, and is said to have been introduced as an ornamental.
Plants that have escaped in various places have become naturalized.

[Uses]
The leaves and roots are used medicinally.

[Cultivation]
Propagate from seed.
If the site is sunny, it is not particular about soil and grows well even if left alone.
In poor light it grows spindly and flowers poorly.
In warm regions it overwinters outdoors.
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.
Fertilizer is not particularly necessary, but for potted plants, slow-release fertilizer placed on the soil once a month is acceptable.
Pests include aphids and slugs.

[Notes]
The Japanese name compares the white, powdery endosperm to face powder.

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