|There are around 100 species in this genus that is native to tropical Africa and Asia. The perennial shrubs and subshrubs have leaves that are oval to lance-shaped and membrane-like. Flowers are tubular in shape and may be either red, pink, yellow, or white, depending on species. Indoors, grow in bright light with moderate water. Outside, plant in full sun, with shelter from direct overhead midday sun. Soil should be fertile, but well drained.