The answer is: Plasmids

* Plasmids: These are small, circular pieces of DNA that exist independently from the main bacterial chromosome. They can carry genes for traits like antibiotic resistance, which can be transferred between bacteria.

Why not in flowers?

* Flowers are eukaryotes: Eukaryotes have their DNA organized within a nucleus, separated from the cytoplasm.

* Plants have chloroplasts: Plants also have chloroplasts, which contain their own DNA, but these are also enclosed within membranes.

In summary: While bacteria have freely floating plasmids, the DNA in eukaryotic organisms like flowers is always contained within membrane-bound structures (the nucleus in the case of flowers).