Yellow oleander (Cascabela thevetia) is a flowering plant renowned for its ornamental value in tropical and subtropical regions globally. Despite its aesthetic appeal, this plant is potently toxic. It belongs to the Apocynaceae family, which includes many toxic species.
Identifying Yellow Oleander
Yellow oleander typically grows as an evergreen shrub or small tree, reaching 8 to 20 feet. Its narrow, lance-shaped leaves are glossy green on top and paler underneath, arranged alternately along the stems. The plant produces large, funnel-shaped flowers, usually bright yellow, but sometimes apricot or peach-colored, which are often fragrant and appear in clusters from summer to fall. These flowers develop into distinct, angular fruits that are initially green, turning black as they mature, and contain one or two nut-like seeds. Native to Mexico, Central America, and the West Indies, yellow oleander is now widely cultivated in warm climates worldwide, including parts of the United States, India, and Australia.
Understanding Its Toxicity
Yellow oleander is highly toxic due to the presence of various cardiac glycosides, such as thevetin A, thevetin B (cerberoside), neriifolin, and oleandrin. These compounds are similar to digoxin and primarily affect the heart by interfering with the sodium-potassium ATPase pump in cardiac cells. This inhibition increases intracellular sodium and subsequently calcium, which can disrupt normal heart rhythm and function. All parts of the yellow oleander plant are poisonous if ingested, with the seeds and fruits generally containing the highest concentration of toxins. Even the milky sap from stems and leaves is toxic and can cause skin irritation upon contact.
Responding to Exposure
Ingestion of any part of yellow oleander can lead to a range of symptoms, affecting gastrointestinal, cardiovascular, and neurological systems. Common initial symptoms include a burning sensation in the mouth, nausea, vomiting, abdominal pain, and diarrhea. More severe effects involve the heart, manifesting as irregular or slow heartbeats (bradycardia) and other life-threatening arrhythmias. Neurological symptoms like dizziness, drowsiness, confusion, and dilated pupils may also occur.
If exposure is suspected, immediate action is necessary. Promptly remove any plant material from the mouth and, if skin contact occurred, wash the affected area thoroughly with soap and water. It is important not to induce vomiting unless advised by medical professionals. Immediate medical attention is essential; contact a local poison control center or emergency services without delay. Providing details about the ingested plant part and amount can assist medical personnel in treatment.