The first two are really good, though the first COULD do with some more brightness, unless you really wanted a flower photo to be so dark.
The third is a blooper to my mind, the background is way too bright, twig and leaves get a purple outline from overexposure and what comes with it (chromatic abberration could be the expression of choice here, but I'm not sure, to be honest), plus with the wrong settings - too slow shutter speed - you got camera shake, too.
The last is a wonderful flower, but the light is the least intersting here.