What Causes a Yellow Violet

Rather than the usual blue-and pink-producing anthocyanins , which belong to a large group of plant compounds collectively called flavonoids, Blansit’s plants contained a group of flavonoids, closely related to the anthocyanins, called flavonols.

It is the flavanols that create the yellow colors in flowers, and Blansit’s Big Yellow was the first reported occurrence of flavonols in African violets.

According to Jeff Smith of Norman, Okla., who was one of the first scientists to examine Blansit’s plants, “Studies of the synthesis of flavonoids in plants indicate that their production is a step-by-step process requiring many different enzymes. The loss of an enzyme is typically a mutation inherited as a recessive trait.

“Yellow African violets,” Smith said, “are the result of the loss of the enzyme needed to convert flavonols into anthocyanins. The flavonols accumulate in the petals instead of anthocyanins and the resulting color is yellow.

“In many species of plants, the failure to complete the anthocyanin synthesis would result in flavonols that are pale in color. Nature, however, has favored Blansit’s African violets with flavonols that contain methyl groups that produce substances which are distinctly yellow.

“The yellow in Nolan’s plants is very distinct, supporting the idea that the conversion failure to anthocyanins is the source for the yellow pigment.”