It is dark marks on the leaves (they are actually red pigment showing through from the reverse side of the leaf). It's not harmful but shows genetic instability.

When some varieties start showing it, the blossoms may change and eventually the whole plant may change permanently. I've experienced this on certain blue and white varieties and taken a non-birthmarked leaf and restarted them.

Diana

Isn't that strange. I haven't seen other plants do that. But, I don't know of too many other plants that have been crossbred and manipulated to get blossoms as much as has been done for african violets........unless maybe it's roses.
Thanks. It's very interesting.
Mary

I suspect they've manipulated some other plants quite a bit too, but I don't know if any birthmark either.

I seem to see it on blue/white ones but maybe's it's just that I have way too many of them.

Sometimes the flowers get really stunning even if it is unstable and I keep the "off" one even while restarting a leaf.

Diana

Be interesting to see some examples of "birthmarked" leaves for those of us who are unfamiliar with them.

HI Mary, Paul, Diana,

Some examples may be viewed at the following page on the website listed below. The owner of the website is no longer selling AVs, from what I have read, however, he left his web pages up for people to read.

African Violet Leaf Problems - Reed's Greenhouse
www.reedsgreenhouse.com/leaves/leaf-id.htmâÂÂ

It includes African Violet leaf photos and images of birthmarks and other conditions.

Diana,
In doing some research on the 'net, I read that it seems to be especially the blue and white violets that are likely to sport and have birthmarks on the leaves.

Joanne

Thanks, Joanne. I knew there should be photos somewhere.

Diana