Lobelia is a genus of flowering plants comprising 415 species, with a sub cosmopolitan distribution primarily in tropical to warm temperate regions of the world, a few species extending into cooler temperate regions. They are known generally as lobelias.
The genus Lobelia comprises a substantial number of large and small annual, perennial and shrubby species, hardy and tender, from a variety of habitats, in a range of colours. Many species appear totally dissimilar from each other. However, all have simple, alternate leaves and two-lipped tubular flowers, each with five lobes. The upper two lobes may be erect while the lower three lobes may be fanned out. Flowering is often abundant and the flower colour intense, hence their popularity as ornamental garden subjects. Lobelias make excellent edging plants in flowerbeds or can be grown in containers and hanging baskets. L. erinus is the most widely cultivated species in the genus. It has been cultivated since the seventeenth century and commonly used in flowerbeds. The rare, L. valida also makes an excellent bedding plant. L. pteropoda from the Transkei area makes an attractive hanging basket specimen. Most species can easily be grown from seed.