Thanks for the reply Ken. The colours and lightning are true to life. One of the leaves is rolled over, which makes it seem as though I have washed the colour out with flash, but is not the case. The problem is that the centre plant has turned pale green, compared to the dark, rich green colour of its neighbours. Lastly, they are in the shade for most of the day. This post was edited by bcca on Mon, Jul 15, 13 at 13:31

I'm attaching a plant that I grow indoors under lights. It's about 3 months old. I've attached a photo of the problem I'm having with one of the leaves. Any ideas? Thanks, bio Image link:

Are they indoors now? I wouldn't worry too much about them during winter - just give them the best light you can. Most important thing is to keep the stems firm and healthy. Pick off the old, diseased leaves and new leaves should appear if conditions are good for growing. Your first description sounded like some powdery mildew which can be hard on certain begonias and just a pest on some others. Spray with a fungicide to keep it under control.

I understand that a number of different "species" are now properly considered B. dregei. I used to have B. partita, which I think I probably got at Kartuz. Whether B. partita, richardsiana, etc. are all independent synonyms or whether they represent "varieties" is an argument for the taxonomists and botanists. However, there is precedent for the use of the term "Begonia dregei var. richardsiana" in a botanical garden's collection (link at bottom). The link to the photo at U. Connecticut seems to no longer work. Whether or not the botanists consider this a variety or a synonym of dregei is not the point. The point is that there are several somewhat different looking plants that were originally given different names. Now all are considered Begonia dregei. I doubt many botanists would object to non-botanists simply calling these different "varieties" of the species. Here is a link that might be useful: Database indicating use of