Allamanda cathartica (golden trumpet, "Ariakekazura")

Japanese name: アリアケカズラ （有明葛）
Scientific name: Allamanda cathartica

[Overview]
In Japan it is treated as an evergreen woody climber, but in hot environments with strong sunlight it becomes shrubby.
It may drop its leaves when the temperature falls.
If the plant is damaged, it exudes a white milky sap.
Young branches grow long and slender.
The leaves are simple, in whorls of 3–4 or opposite, oblong to obovate, 6–15 cm long, glossy on the upper surface, and hairy only on the midrib of the underside.
The leaf margins are entire.
It flowers all year round if the temperature is high enough.
The flowers are borne at the branch tips; they are yellow, funnel-shaped, 5–7 cm across, and 5-lobed at the tip.
The fruit is a spherical to elliptical capsule about 3 cm across, covered with soft spines.
The seeds are flat and winged around the edge.

[Cultivation]
Propagate mainly by cuttings, but seed and grafting are also possible.
For cuttings, wash off the white milky sap from the cut end before inserting them.
It prefers a sunny, well-drained, fertile soil.
In warm regions it is vigorous and grows well regardless of soil type, and in Okinawa it is widely used for greening.
In regions with frost, grow it in a pot and bring it indoors to a sunny spot in winter.
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 dries out.
Apply slow-release fertilizer placed on the soil from spring to autumn.
It sprouts vigorously and grows thickly, so prune as appropriate.
Pests and diseases include sooty mold, damping-off and aphids.

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