page_title: Streptocarpus
section_title: Genes and inheritance
hierarchical_section_title: Streptocarpus / Cultivation / Genes and inheritance
caption_attribution_description: English: Streptocarpus saxorum in bloom
context_page_description: A popular house plant, Streptocarpus, is an Afrotropical genus of flowering plants in the family Gesneriaceae. The genus is native to Afromontane biotopes from central, eastern and southern Africa, including Madagascar and the Comoro Islands. The flowers are five-petalled, salverform tubes, almost orchid-like in appearance, and hover or arch over the plant. In the wild, species can be found growing on shaded rocky hillsides or cliffs, on the ground, in rock crevices, and almost anywhere the seed can germinate and grow. For the home, there are now many hybrids of various colours and forms available.
  Although generally referred to simply as "Streptocarpus", or "Streps", the common name for subgenus Streptocarpus is Cape primrose, referring to the nativity of several species to South Africa and their superficial resemblance to the unrelated genus Primula. The common name for subgenus Streptocarpella is nodding violet. Saintpaulia is a separate section within Streptocarpus subgenus Streptocarpella.
  There are a few odd Asian species of Streptocarpus that however do not belong in the genus.
context_section_description: Flower Color Genes in Streptocarpus 
  The following is adapted from an overview provided by Dr Jeff Smith at Ball State University, US.
  The following is a quick summary of 1950s publications by Lawrence and Sturgess,
  Colour genes
  V = places pigment in the flower stems
  F = places pigment in the petal cells
  V and F are both necessary to give color, but do not control which color.  When V or F are recessive (vv or ff) the flowers will lack any color and will be white in appearance.
  I = color intensity. II = intense color, Ii = medium color and ii = pale color. This gene doesn't control "which color", just how "intense" the final color will be in appearance.
  The actual flower color genes are named O, R, and D.  Where the second copy of the gene is given as a "_", the second copy can be either dominant or a recessive. For example, in Blue flowers, only one dominant of each the three genes is needed (e.g. the O gene could be either OO or Oo, and it wouldn't matter which).
  Blue = O_R_D_
  Magenta = ooR_D_
  Pink = oorrD_
  Mauve = O_R_dd
  Rose = ooR_dd
  Salmon = oorrdd
  Other genes affect the pattern of color or modify the final color. Some of these genes are:
  B = gives a blotch of color in the throat of the bloom. The recessive "bb" produces flowers without a blotch. The trait appears to produce a darker or more intense version of the color of the outer edges of the petals. Thus, you can get dark pink blotches on a lighter pink flower etc.
  H = gives color on the capitate hairs of the pistil. The recessive "hh" gives white or colorless hairs.
  Genes F, I, B, and H are very closely linked and are usually inherited as a single unit. Therefore, many plants have pigmented flowers with at least medium intensity of color, and blotches in the throat, or have white flowers without blotches.
  C = adds a co-pigment to the flower color. This gene modifies the appearance of the color, giving a bluish tint to the overall color. Plants with the recessive "cc" combination have flowers that are "brighter" in appearance. In the Mauve-Rose-Salmon series, the dominant gene produces undesirable murky colors.
  L = puts nectar guides in the flower tubes. The recessive "ll" produces flowers without the lines.
  Y = puts a yellow central stripe in the flower tube. I suspect that the size of the yellow area changes with "YY" versus "Yy" plants. The recessive "yy" would produce flowers with no yellow in the flower tube.
  Other genes are mentioned in the original articles, but they appear to involve some rarely seen color modifications. Genes for plant size, fragrance etc. were not mentioned in these articles.
caption: Streptocarpus saxorum in bloom
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