The flowers, or members, of the Solanaceae (Nightshade) family are trumpet-shaped and highly fragrant. Most types only open at night, and only then release their haunting scent. Several different species of flowers in the nightshade family are referred to as "angel's trumpets."
The plant most often referred to as "angel's trumpet," burgmansia (Burgmansia solanaceae) is a hardy tropical perennial. It grows as a small tree or shrub to a height of 8 to 10 feet and spreads up to 12 feet wide if not pruned. Burgmansia's trumpet-shaped flowers hang down, with their open ends facing the ground. The flowers open during the evening and emit a hauntingly sweet scent. They are most often yellow, but can also be white or pink. Grow burgmansia in full sun and fertile, well-drained soil. They like a lot of water and will need supplemental irrigation during much of the growing season.
A sprawling vining plant that quickly grows 2 to 3 feet high, datura (Datura spp.) is another trumpet-shaped flower referred to as angel's trumpet. Most often white, they are nearly identical to the flowers of burgmansia. Datura holds its blossoms up during evening when it releases its sweet fragrance. Grow it in full sun to partial shade, although it will prefer shade in hotter areas.
Closely related to the tobacco grown for smoking, nicotiana (Nicotiana alata) is a perennial that is most often grown as an annual. It can grow up to 5 feet high and produces trumpet-shaped flowers sometimes referred to as "angel's trumpets," similar to other species in the nightshade family. The flowers release their fragrance at night. Flowers can be white, red, pink, green and bicolor. Although it will grow in partial shade, it prefers to grow in full sun in average, well-drained soil. Nicotiana is a prolific reseeder. Save the tiny seeds of species varieties and mix them with sand before scattering them in your garden, where they will readily sprout and grow.