Technical issues

Flowers and plants can be good subjects for you to practice your photography skills; however there are already millions of such images in the Adobe database. In order for yours to be accepted they need to be unique and perfectly executed. In general, your images exhibit a DOF that is too shallow, lack of sharp focus, and too closely cropped. Search the Adobe stock database for each of the flowers you've posted; look at orchids for instance and see how other successful photographers have lit, framed and exposed their frames. This will give you an idea if the quality level that is expected.