Are both Nerium or Thuja could be a shrub?
Thuja Thuja ( ) is a genus of coniferous trees in the Cupressaceae (cypress family). There are five species in the genus, two native to North America and three native to eastern Asia. The genus is monophyletic and sister to "Thujopsis". Members are commonly known as arborvitaes, (from Latin for "tree of life") thujas or cedars.
Strophanthus welwitschii Strophanthus welwitschii grows as a deciduous shrub or small tree up to 5 m tall, or as a liana up to 8 m long, with a stem diameter up to 10 cm . Its fragrant flowers feature a white turning purple corolla, creamy and red or purple-streaked on the inside. Its habitat is forests or rocky woodlands from 300 m to 1800 m altitude. "S. welwitschii" is used in local medicinal treatments for respiratory conditions, gonorrhoea and scabies. The plant has been used as arrow poison. "Strophanthus welwitschii" is native to Democratic Republic of Congo, Tanzania, Angola and Zambia.