Calibrachoa is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of plants in the Solanaceae

Solanaceae

Solanaceae are a family of flowering plants that include a number of important agricultural crops as well as many toxic plants. The name of the family comes from the Latin Solanum "the nightshade plant", but the further etymology of that word is unclear...

 (nightshade) family. They are weak evergreen

Evergreen

In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...

 short-lived perennials

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

 and subshrubs with a sprawling habit, and they have small petunia

Petunia

Petunia is a widely cultivated genus of flowering plants of South American origin, closely related with tobacco, cape gooseberries, tomatoes, deadly nightshades, potatoes and chili peppers; in the family Solanaceae. The popular flower derived its name from French, which took the word petun, meaning...

-type flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

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

Calibrachoa are closely related to the petunia. However on further examination it has been found that there are major differences in chromosome

Chromosome

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

s, corresponding to external differences and fertilization factors that distinguished Calibrachoa from the petunias. Calibrachoa is named after Antonio de la Cal y Bracho, a 19th century Mexican

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 botanist and pharmacologist.

Cultivation

Some of these are kept as ornamental plant

Ornamental plant

Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...

s, the hybrids (Calibrachoa x hybrida) being popularly known as "Million Bells". The plants can tolerate light frost and thrive in sun or semi-shade. Plant in a free-draining soil and water only when the soil is almost dry. Propagate from tip cuttings.

Species include:

• Calibrachoa caesia
• Calibrachoa calycina
• Calibrachoa dusenii
• Calibrachoa eglandulata
• Calibrachoa elegans
  Calibrachoa elegans
  Calibrachoa elegans is a plant species in the genus Calibrachoa found in Minas Gerais in Brazil.-External links:...
  
  
• Calibrachoa ericaefolia
• Calibrachoa excellens
• Calibrachoa hassleriana
• Calibrachoa heterophylla
• Calibrachoa humilis
• Calibrachoa linearis
• Calibrachoa parviflora
  Calibrachoa parviflora
  Calibrachoa parviflora is a species of flowering plant in the nightshade family known by the common name seaside petunia. It is native to much of southeastern South America, Mexico, and the southwestern United States, and it is present as an introduced species in other sections of the Americas,...
  
  
• Calibrachoa pygmaea
• Calibrachoa rupestris
• Calibrachoa sellowiana
• Calibrachoa spathulata
• Calibrachoa thymifolia