(Click to embiggen.)
The picture in question appeared to be a twitter item from @san_kaido:
The apparent translation, found at various websites is,マーガレットの帯化(那須塩原市5/26)② 右は４つの花茎が帯状に繋がったまま成長し，途中で２つに別れて２つの花がつながって咲いた。左は４つの花茎がそのまま成長して繋がって花が咲き輪の様になった。空間線量0.5μSv地点(地上高1m) pic.twitter.com/MinxdFgXBC— 三悔堂 (@san_kaido) May 27, 2015
"The right one grew up, split into 2 stems to have 2 flowers connected to each other, having 4 stems of flower tied belt-like. The left one has 4 stems grew up to be tied to each other and it had the ring-shaped flower. The atmospheric dose is 0.5 μSv/h at 1m above the ground."
Alarming? Isn't it?
Allow me to explain why. Go to Google and type in (without quotes): "Mutated Daisies -Fukushima"
For those unfamiliar with different search query techniques, the minus sign (-) in a search will find you all results that do not include the keyword following it. This brings up an uncountable number of pages with pictures of mutant daisies. This kind of mutation is actually fairly common among daisies. Actually, mutations are incredibly common, period. In humans, the background rate of birth defects is five to ten percent. That is astonishingly high if you think about it. Of course, it counts a lot of relatively harmless birth defects. I have a congenital mitral valve regurgitation (heart murmur) that I was born with. It only causes me mild discomfort about once or twice every six months or more. You might have a birth defect you don't even know about.
What causes these defects? Well, it might be simpler to list the things that don't cause birth defects, like aliens from the planet Xlorrbnacht 2. The fact is that background radiation (radiation from the sun, various naturally occurring minerals, radioactive byproducts from burning coal), chemicals (including naturally occurring chemicals from food we eat), and various other factors combine to create a non-zero chance that a given person will be born with some kind of birth defect or another.
So how do I know that this daisy wasn't mutated by radiation leaked from Fukushima? I don't. For one thing, I'm not a plant biologist, so I don't know what kind of mutation this is. For another thing, I don't know if the overall rate of that particular mutation has increased appreciably above the background rate. I only see one plant. What I do know is that the person who took the photo mentioned that the radiation in the area was 0.5 μSv/h. That's possibly lower than the radiation dose I'm receiving as I type this here in the Midwestern United States, because I'm sitting in a basement in an area rich in limestone. Could the plant have mutated due solely to normal background radiation? Yes. You or I could too. That's where a lot of cancers and birth defects come from. But I strongly doubt it has anything whatsoever to do with the disaster at Fukushima.
The major media outlets haven't yet picked up on this photo, and I really hope they don't, at least not without a competent scientist on hand to explain what people are actually looking at. But, you don't really need one. All you really need to evaluate this photo is Google and a minus sign.