With new streets and regions opening it's only logical that new trees must be introduced as well!
A few of my ideas:
. Cotton Tree
Harvesting this warm and fuzzy tree would produce, well, cotton! The cotton itself would be used to craft fabric and textiles, which could be used to create carpeting for one's house (through the 'Carpentry' skill? ;P).
I imagine the Cotton Tree to be pink in colour, and having a motherly and affectionate personality.
Furthermore, the cotton could be used to make 'Cotton Candy' through the cooking skills, which would also be suitably pink in colour. :)
. Venus Butterflytrap
This carnivorous plant works quite differently to all the others. But that's good right? Diversity is always needed in Ur! I would expect to see this one in jungley type areas, rainforests etc.
Every once in a while Butterflytraps will effectively gobble up butterflies that hover too close to their alluring jaws, and start digesting them! Now this is where it gets interesting. You can not harvest a trap when it is empty, it is only when it is digesting a butterfly do you pet it, and coax it to allow the little butterfly free! (possibly giving it meat or other meatfoods in substitution).
You are obviously provided with some kind of reward, and the butterfly is let free with a "THX SOO MUCH!!11!oneone!1", or something along those lines.
If butterflies are left in there too long, they are eaten - a good way to relieve streets of crowding.
I probably like this one the most, as it fits in the whole idea off the collective community being responsible for maintaining Ur, if nobody's freeing butterflies.. well they die.
. Pine Tree
Finally to fit the new snowy regions of Aranna we would have Glitchmasy looking Pine Trees.
These would come from seasoned beans that look like a pine cone. I was thinking that they could possibly grow decorative ornaments, like baubles. I am not entirely sure what baubles could be used for in the game yet, but nevertheless it would be a resource for making things (possibly housing decorations).
Each Pine Tree would have a single star at its very top, like harvesting the last egg, to get the star would mean all the baubles are gone, and is quite the achievement. As such, stars would be rare, and could very well be used to make fantastical things!
Hope I made all that understandable enough, these are just the beginning concepts, tell me what you think. :)