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 amboensis Strophanthus amboensis grows as a deciduous shrub up to 4 m tall, or as a liana up to 20 m long, with a stem diameter up to 20 cm . Its flowers feature an orange-yellow turning purple corolla tube, white-streaked on the inside. Habitats are forest margins, scrubland or rock fissures, from 450 m to 2000 m altitude. "S. amboensis" is used in local medicinal treatments for rheumatism, venereal diseases and scabies. The plant has been used as arrow poison. "Strophanthus amboensis" is native to Democratic Republic of Congo, Angola and Namibia.