Cheiranthus mutabilis, the Purple, winter-flowering Wallflower is a gorgeous plant. I love it.
I actually do not grow this plant in my own yard (for reasons which I cannot explain). I have planted it at the CTC@Robertson, and Dorothy and Bernie have it growing where they live, in Bowral. This is their plant.
The buds appear as a purple rosette. The colour comes from the colour of the bracts which cover the flowers before they open. Then as the first sign of the petals appear, they show as bright orange.
Purple and orange - what a combination? Interior designers would scream at the thought of matching those colours. But it works in nature.
As the petals first unfurl, the bright orange petal opens as a pale peachy yellow, and turns almost immediately to a buff-brown. The petals are suffused with pigments which darken as the flower ages. So yellow flowers change through a pinkish tone to purple. It is an extraordinary transformation.
Some modern forms of this plant are all purple, but, like many "improved varieties" of flowers, it is surely a retrograde step to remove its greatest charm - its changeability of colour - the "mutability" for which it is named. It is precisely this amazing colour variation which I love. How do the natural plant pigments achieve this colour change as the flowers mature? I wish I knew the chemistry involved.
This flower is very attractive to the Hover Fly, which itself is an adornment to any flower.