What are the characteristics of yellow oleander? A deeper look at yellow oleander
Other names for yellow oleander
Yellow oleander, an upright shrub plant, is also called yellow allamanda.
Origin of yellow oleander
This species is native to Brazil and is now widely cultivated in tropical regions. It is cultivated in gardens in Guangxi, Guangdong, Fujian, Taiwan, China and Beijing (in greenhouses) in China.
Morphological characteristics of yellow oleander
Yellow oleander is about 1-2 m tall, has milky sap, and its branches are grayish white.
The leaves are whorled in groups of 3-5, entire, mostly elliptical or obovate-oblong, about 6-12 cm long and about 2-4 cm wide. The leaf tip is acuminate or acute, the base is cuneate, the upper surface of the leaf is dark green, and the underside is light green. Except for the midvein and lateral veins on the underside of the leaf, which have fine hairs, the rest is hairless.
The veins are flat on the upper leaf surface and raised on the underside. There are 7-12 lateral veins on each side, which anastomose before reaching the margin; the petiole is very short, and glands are present at the base and in the axils.
The cyme of yellow oleander is terminal, the pedicel has fine hairs, the flowers are yellow, 4-6 cm long, about 4 cm in opening diameter, and the bracts are lanceolate, borne at the base of the pedicel.
The corolla is funnel-shaped, with reddish-brown stripes inside. The lower part of the corolla is cylindrical, no more than 2 cm long, 2-4 mm in diameter, swollen at the base. The throat expands upward into the limb, about 3 cm long and about 1.5 cm in diameter. The top of the limb is 5-lobed, the corolla lobes overlap to the left, and the lobes are ovate or circular, obtuse at the tip, 1.6-2.0 cm long and about 1.7 cm wide.
Yellow oleander has 5 stamens, growing in the throat of the corolla tube. The filaments are relatively short, with fine hairs at the base. The anthers are ovate and relatively blunt at the tip. The disk is fleshy and entire, the ovary is entire, 1-loculed, the style is filiform, the stigma is obtuse at the tip and ring-shaped at the base.
The capsule of yellow oleander is spherical, with long spines, about 3 cm in diameter. The seeds are flat, with a membranous margin, about 2 cm long and about 1.5 cm wide. The flowering period is from May to August, and the fruiting period is from October to December.