The cultivars of the Chimera®-group are exclusively chimeral plants. The distinction between the Chimera®-group and the present day assortment is that not one but at least two sets of genetic information determine the appearance of the plant. Consequently different tissues of a chimeral plant have a different genetic background. At times the genetic differences are so small that they remain practically unnoticed. This is not the case, however, with flower chimeras. Attention has been directed towards this group for quite some time. The central bar of the petal has another genetic composition (type A) than the outer section of the petal (type B). The result is the expression of two different colours. This in turn yields the characteristic image of a spoke-wheel. Hence the term pinwheel flower (see fig. 1)
Among the present Saintpaulia assortment bicoloured cultivars occur. In all cases this term applies either to the combination of white with a particular colour, or to different intensities of one and the same colour. In the latter case the colour·intensity is highest in the outer edge of the flower, or eversely in the "eye" of the flower. In the case of a combination of white with another colour, the outer edge of the petal may be pigmented, lighter in colour, or even unpigmented. Flower chimeras differ from bicolour African violets in that besides combinations of white and colour, other colour combinations - such as, for example, pink/red or pink/blue are possible as well. Moreover, there is a difference in colour pattern: the central bars of the pinwheel flower run from the center of the flower almost up to the edge of the petals (see fig. 2)
It is a well known fact that bicolour African violets are not stable. All the cells of the petal contain the same genetic information for the forming of a pigment. But due to the presence of a certain factor, the forming of pigment is blocked in some places, and as a conce quense the colour remains unexpressed. Unfortunately, this appears to be a relatively unstable feature. In nearly all cases the bicolour culti·vars will gradual ly turn into partly or wholly pigmented flowers. The colour pattern of the pinwheel flower is the result of the forming of two different pigments, or of a complete suppression of pigment·formation in the white sections of the flower. From the above it will be evident that unlike bicolour African violets, flower chimeras have a characteristic pattern of stable colour combinations.
The characteristic pattern of the pinwheel flower, the noticeable colour-combinations, and the stability of the colour are guarantees of the undeniable decorative value of flower chimeras.
When chimeras are propagated in the usual way by leaf cuttings, the chimeral character will be lost in the newly formed plants. The reason for this is that the shoots developin the outer cell·layer of the leafstalk. Every individu al cell in this layer contains the same genetic information, viz. type B (see fig. 1). In the meristem of the growing top the chimeral character is maintained. The shoots which develop in the axillas of the leafstalks (suckers) also hold on to their chimeral character. This complication entails that flower chimeras can only be produced via the help of alternative propagation techniques.
From the fact that Chimera®-African violets cannot be propagated in the traditional way, it can be concluded that they will occupy their own special place next to he existing highquality cultivars. Chimera®-African violets indeed are a group of their own.