Nope, it is produced largely (about 70%) by algae, which are sometimes called “marine plants” but are mostly single-celled organisms.

Flowers didn’t just spontaneously evolve and give rise to bees. Flowers as such that we see today evolved *because* of flying insects feeding on them, and are often a particular shape to enable particular pollinators (e.g. bees) and to prevent others (ants) from stealing the pollen. (And yes, there is a lot of very inaccurate shortcuts in this terminology because of course the plant didn’t sit down and consider its continuing survival strategy — gradual changes in one direction or other helped offspring survive in face of ants or bees over thousands of generations, while gradual mutations helped ants or bees survive their changing environment, but we hopefully all know that). It is a slow and gradual co-evolution — it might be triggered in a mutation in a plant or a new insect behavior evolving, but neither would happen without the other. Were the plants the chicken or the egg? If you catch my meaning.

And none of them would be here if not for the cyanobacteria who were the first to convert early Earth’s carbon dioxide atmosphere to oxygen, likely while killing most of previous life.

We all like simple, decisive, causal explanations, but they only work in hard sciences, and even there, the quantum nature of reality is starting to mess with us. Life is unfortunately never as simple or causal as Newtonian Physics.