I think Nolan could bring Ivy into his vision with success....minus the giant mobile plants and green skin.
Here's a small concept I haven't really thought out in depth...would love to see someone dig the idea and run with it:
Career: Biochemist with a focus in botanical biochemistry. Maybe works for a pharm or cosmetic company.
In keeping with Nolan's "realistic" vision, Ivy could be a poison eater...which is a very real activity that's existed in just about every culture and time period, including today in america. Ex:Bill Haast has injected himself with snake venom for decades and has built up an amazing tolerance to many venoms that would easily kill the average healthy adult.
Source:
http://archive.southcoasttoday.com/daily/02-96/02-19-96/2snake.htm
By eating/injecting/*****ing (HA!) with increasing amounts of various toxins, Ivy could certainly kill with poisoned lipstick or perhaps even her own body fluids.
As for her love of plants, there is a sexual attraction some people (albeit very few people have) to plants where they are only able to become aroused when plants or trees are involved...The name of this paraphilia escapes me but I think it's Chlorophilia...it's not always sexual but more often than not is.
I read a book called The Science of Super Villains which had an entire chapter dedicated to the vixen of vines and I seem to remember something being said about photosynthesis taking place in the eyes. Here's a link which discusses this somewhat...but not so much from a scientific POV:
http://newconnexion.net/articles/index.cfm/2004/11/manek.html
So perhaps Ivy isn't too unrealistic for Nolan's Batman world.
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