Reddit mentions of Carving Realistic Flowers, Revised Edition: Morning Glory, Hibiscus, Rose: Ready-to-Use Patterns, Step-by-Step Projects, Reference Photos (Fox Chapel Publishing)

If you want to take it to the next level check out Carving Realistic Flowers In Wood, the projects are all done with power carving but you could do 99% of the work with a knife if you took your time. You'd probably need some files or special gouges to do some of the curved bits without power.

For your carving I think it's a good job as a beginner. I would say you just need to pay more attention to grain and to take the time to clean up the fuzzy's and little slivers in your corners, it would take it up a big notch.