Color Variegated Nicotiana

It's been so hot here, that I haven't been spending too much time outside to take pictures. I took this shot early this morning after watering my garden. This is another of the Nicotiana plants that re-seeded itself in my garden from some plants that I had planted last year. I remember my father, who was a plant pathologist, telling me that this type of unusual color variation in flowers is caused by a virus. Since Nicotiana is a member of the tobacco family, this is most likely a form of tobacco mosaic virus. It's kind of pretty though and fortunately the virus doesn't seem to affect the health of the plant in any other way.