Zyras fantasy and high points in my opinion
http://art-of-lol.com/wp-content/uploads/2014/06/zyra-league-of-legends-27753-3840x2160.jpg
Disclaimer: I literally only play support Zyra. I tried her a few times mid and it just wasn't fun in my opinion.
When asked the question: What is the Zyramerican dream?
There's absolutely no topping the Zyra all-in, for me (bush assassin zyra is pretty fun but malzahar is better at it). Both teams are grouped, I sit behind my front line - waiting, waiting for my moment to strike. As soon as the entire enemy team is clumped or oraganized in a single file line, that's the moment I flash into them with E > W > Q > W > R (the full combo). These flashy moments signal an alarm in the brains of my solo queue team telling them it's time to fight. Usually it turns out as a won teamfight because of Zyra alone being such a powerful presence in the right scenario (enemy clumped).
The chat is usually filled with praise such as "the zyra god", "so ballsy", or something along those lines, but to me, that's just how Zyra should be played.
For any other champion it would be suicide, because it is. Zyra is able to shred the entire enemy team and cc them long enough for your allies to react. As Zyra I either die in the process and take advantage of her passive to shred the enemy even more, or just high tail it out of there (or zhonyas). Once Zyra has expended her full combo the most she can do is use her snare for peel/chase and Q to do some more shredding.
Despite being covered in thorns, Zyra can't poke, she can't siege, and she can't really create control zones. She's an all-in mage that can also initiate and that's why I love to play her. Her plants are not turrets for sieging or control, that's what Heimerdinger does and that should remain his niche. I think her current playstyle matches pretty well with her lore. She's not a "plant mage" that bends plants to do her will from afar (like azir and his soldiers), she IS the jungle and I think that's awesome. She entangles multiple enemies in a circle of death that also makes her plants supercharged and because she would normally die when flashing into the enemy team, she herself becomes another plant in the jungle.
I'm not saying her passive is the best, but I think it matches her playstyle of throwing herself into danger in order to unleash the full combo (unlike kog'maw who wants the exact opposite :/ ) as well as matching her lore of "being a jungle". I think having terrain interactions would be neat, andbeingabletobebrieflyuntargetablewouldbecoolnotroll.
But please, please don't rework her into Heimerdinger 2.0. Her plants are an extension of her abilities, not her main niche.
But hey, that's just me.
Random Fact: The heaviest living organism in the world is a giant tree (system) called "Pando", consisting of about 43,000 genetically identical aspen trees connected through their roots.