So I'm fairly new and wanted to see if any of you could help me understand the print issue i am seeing.

I wanted to print this flower pot that had a cool ring design on it but it failed both times i have tried (see photos below).  I had a some concerns about the bottom of each ring not being supported enough and causing issues but at 0.2 and 0.16 layer height the slicer did not recommend supports which confused me. 

I want to call this defect stringing but i don't think that is correct so if not, what would this defect be called?

Is this caused by the lack of supports and if so why would the slicer not recommend them?