What do you have in your DS setting in terms of useful plants?
Bamboo is incredibly useful yet does not appear present in the setting material, but previous Age plants like the orange tree have survived.
Spices, herbs, tubers, roots, fruits, vegetables.
Are there normal-sized bees to pollinate, or are there other pollinators?
Have you seen the Netbook of Athasian Ecology? It has some good ideas in it, some of which I’ve used. However specific types of plants have never been of much importance in my games unless it’s a Tree of Life, trying to eat the party, or otherwise supernatural.
Just downloaded and starting to read. Thanks 
Bamboo is canon. Check out the Chn’thrang description from the first 2E monstrous compendium.
There are a lot of plants in Dark Sun, in short i almost know the mayority just reading the novels (The Prism pentad and the Tribe of One sagas, among others): blue pagafa trees, agafari tree, and plants only flower during the times of monzon or the pass of the cerulean storm or similar events
Mostly plants are mutated, smaller version of common plants adapted to the hotness of Athas, such as agafari is a really hard (like metal) black wood whose description make me remember of the color of the ebony tree
I find myself agreeing with the Netbook’s need for changes being brought to the biosphere to make it realistic (enough).
27 years after encountering DS I find myself compelled to make changes, some simple, others sweeping. I know I am not alone in this.
Certainly not. Frankly, I think a major reason why I want to see Dark Sun officially revived in 5e is not to see what’s the same, but what changes have been made that effect the setting for the better. Being able to look back and do things differently is a powerful tool, and one of the reasons why 4e Dark Sun resetting the timeline was so well received, even if it wasn’t perfect.