In some hybrids, the outer color zone occupies almost the entire petal and the distal segment of the midrib in those hybrids is correspondingly very long, nearly reaching the base of the petal. For the sake of brevity, the term midrib in this catalogue will refer to the most apparent segment of the midrib, which in the great majority of hybrids is the distal segment. Though rather narrow, it is wider than the midrib and also differently colored. The stripe possibly serves as a honey guide for insects. Two or more color regions of the petals form distinct color patterns.
Most hybrids show only one particular pattern, but in some two different patterns are developed.
Petals of Type 1 are characterized by the presence of both a well-developed outer color zone and inner color zone. Two subtypes can be distinguished. In Type 3, however, a basal stripe is not present and the distal segment of the midrib is very long, nearly reaching the base of the petals. However, a suggestion of an outer color zone is indicated by the presence of a pigmented distal midrib segment, this marking associated with an outer color zone in the above color patterns. Of interest, outer and inner color zones are more or less recognizable in the outer petals.