One of the first spring wildflowers to grace the woods here in Michigan are the Round-lobed Hepatica. This beautiful little flower ranges in color from white to magenta to a deep rich purple-blue. They can be found growing in hardwood forests more often than not on south facing hillsides. They face south in order to get maximum exposure to the warming sun at this time of year. They are also unusual in that they close down late every afternoon and only open up on sunny days when the temperature is above 50. I think this is likely to protect the delicate flowers from the colder temperatures at night this early in the spring.
The good news is that if you want to photograph Hepatica you get to sleep in! I usually head out about 10 AM on warmer days to give them a chance to open up. Remember these flowers only open up on sunny day. So if there are not some clouds up in the sky to cut the light you are going to want to bring along a diffuser to shade your subject. I usually get my shot all set up and wait for a passing cloud to soften the light or use my diffuser to shade the subject. By diffusing the harsh light we diminish the shadows and over all contrast in the image which lets the beautiful details of this tiny flower come through.
Good luck and good light
Steve
Image: Round-Lobed Hepatica & Tree Bark