Rhododendron simsii is a rhododendron species native to East Asia, where it grows at altitudes of 500–2700 meters. It is a shrub that grows to 2 m in height, with leaves that are ovate, elliptic-ovate or obovate to oblanceolate, 1.5–5 by 0.5–3 cm in size. Flowers range from white to dark red. Some species of Rhododendron simsii are poisonous due to presence of grayanotoxin . It is a shrub that grows to 2 m in height, with leaves that are ovate, elliptic-ovate or obovate to oblanceolate, 1.5–5 by 0.5–3 cm in size. Flowers range from white to dark red. Some species of Rhododendron simsii are poisonous due to presence of grayanotoxin.