Oleander (Oleander leaves)

Description

Nerium oleander is a shrub or small tree in the dogbane family Apocynaceae, toxic in all its parts. It is the only species currently classified in the genus Nerium. It is most commonly known as nerium or oleander, from its superficial resemblance to the unrelated olive Olea. It is so widely cultivated that no precise region of origin has been identified, though southwest Asia has been suggested. The ancient city of Volubilis in Morocco may have taken its name from the Berber name oualilt for the flower. Oleander is one of the most poisonous commonly grown garden plants. Oleander grows to 2–6 m (6.6–19.7 ft) tall, with erect stems that splay outward as they mature; first-year stems have a glaucous bloom, while mature stems have a grayish bark. The leaves are in pairs or whorls of three, thick and leathery, dark-green, narrow lanceolate, 5–21 cm (2.0–8.3 in) long and 1–3.5 cm (0.39–1.38 in) broad, and with an entire margin filled with minute reticulate venation web typical to Eudicots. Leaves are light green and very glossy when young, before maturing to a dull dark green/greenish gray. The flowers grow in clusters at the end of each branch; they are white, pink to red, 2.5–5 cm (0.98–1.97 in) diameter, with a deeply 5-lobed fringed corolla round the central corolla tube. They are often, but not always, sweet-scented. The fruit is a long narrow pair of follicles 5–23 cm (2.0–9.1 in) long, which splits open at maturity to release numerous downy seeds. Nerium oleander is either native or naturalized to a broad area from Mauritania, Morocco, and Portugal eastward through the Mediterranean region and the Sahara (where it is only found sporadically), to the Arabian peninsula, southern Asia, and as far east as Yunnan in southern parts of China. It typically occurs around stream beds in river valleys, where it can alternatively tolerate long seasons of drought and inundation from winter rains. Nerium oleander is planted in many subtropical and tropical areas of the world. On the East Coast of the US, it grows as far north as Virginia Beach, Virginia, while in California and Texas miles of oleander shrubs are planted on median strips. There are estimated to be 25 million Oleanders planted along highways and roadsides throughout the State of California. Because of its durability, Oleander was planted prolifically on Galveston Island in Texas after the disastrous Hurricane of 1900. They are so prolific that Galveston is known as the 'Oleander City'; an annual Oleander festival is hosted every spring.