They are found across much the same region of South America as petunias, from southern Brazil across to Peru and Chile, inhabiting scrub and open grassland.

[2] Calibrachoa was named by Vicente Cervantes after Antonio de la Cal y Bracho,[3] a 19th-century Mexican botanist and pharmacologist.

Calibrachoa are small shrubs or herbaceous plants with woody shoot axis that grow annual or perennial.

The flowers are usually zygomorphic, the bud cover is reciprocal in most species, the only exception is Calibrachoa pygmaea in both cases.

[5] 28 species, including:[6] Some Calibrachoa are cultivated as ornamental plants, popularly known as "Million Bells".