DSC00308.jpg - underexposed and not well composed with a blue-ish white balance. Depth of field is too shallow and almost nothing seems to be in focus.
DSC00335.jpg - same issues
DSC00676.jpg - same issues, plus chromatic aberration.
Did you do any editing on these images or are they straight out of camera? Virtually every images requires editing prior to submission. You'll need to learn those tools (Lightroom & Photoshop) to be successful at stock photography.
Shooting images of flowers and plants can be fun and good practice for your photography and editing skills; however Adobe Stock is already overrun with such images. There are more than 29 million images tagged with "flower". Yours would have to technically perfect and unique in some way to ever be sold.
