.cv is an abbreviation of Cultivar, generally regarded as a blend of “cultivated” and “variety”, but could also be derived from “cultigen” and “variety”. A cultivar is not the same as a botanical variety.

Dahlia is a genus of bushy, tuberous, herbaceous perennial plants native to Mexico. A member of the Asteraceae [or Compositae], dicotyledonous plants, related species include the sunflower, daisy, chrysanthemum and zinnia. There are 42 species of dahlia, with hybrids commonly grown as garden plants. Flower forms are variable, with one head per stem; these can be as small as 2 in [5.1 cm] diameter or up to 1 ft [30 cm] or “dinner plate”.

Photos: Flower Dome, Gardens by the Bay, Singapore [20150131]

Source: Wikipedia