Thevetia thevetioides (Giant Thevetia) - A small, open, evergreen tropical tree from Puebla and Oaxaca Mexico that grows typically as a large shrub in Southern California where it reaches to 15 feet tall and is sparsely foliaged with attractive dark green leaves at the branch tips; the linear leaves are 3 to 6 inches long by ½ inch wide with the edges rolled underneath and pronounced veins on underside of the leaf. From mid-summer to late fall this plant produces showy 4 inch wide bright yellow funnel-shaped flowers.
Cascabela thevetia, commonly called yellow oleander, is native to the West Indies, southern Mexico and Belize. It is a tropical evergreen shrub or small tree that is in the same family as and closely related to Nerium oleander, commonly known as oleander. Primary differences between the two oleanders are: yellow oleander has yellow flowers and alternate leaves and oleander has pink or white flowers with leaves in whorls of three. Yellow oleander will grow to 20-30’ tall in its native habitat, but much shorter in the St. Louis area. It is an upright shrub that features willow-like, linear-lanceolate, glossy green leaves (to 6-7” long) with distinctive midribs and large 3” long funnel-shaped sometimes-fragrant yellow (less commonly apricot) flowers in few-flowered terminal clusters (cymes). Flowers bloom from summer to fall. Flowers give way to black seed pods, each containing 1-2 nut-like seeds. As with many of the dogbane family members, plant stems exude a milky sap when cut and all parts of the plant are poisonous if ingested. Plant saps can cause allergic skin reactions in some people. Smoke from burning plant material can also be toxic. May be trained as a standard. Seeds (1” diameter) are sometimes carried as talismen in the West Indies, where the shrubs are also commonly called lucky nut.
Synonymous with Thevetia peruviana and Cascabela peruviana.
Genus name comes from the Spanish word cascabela meaning small bell in reference to the shape of the flower.
Specific epithet honors André Thevet (1502-1592) a French monk who traveled in Brazil and Guiana.