I am a first year student studying biology at university.And we have to
elaborate a file whose subject is the evolution of some plants in specific
climates, like cactus, nenuphares, algue and carnivorous plants.

Boy, is Cereoid going to chop you down! Your topic is much too broad. Algae are
not even considered real plants, as far as I know. This reminds me of the story
of the Roman soldier who came to Hillel and said, "Tell me all about the Torah
while I am standing on one foot."
One of my favorite books is "Flowering Plants, Their Origin and Dispersal."
Don't remember the author. However, it is not new & there may be more
up-to-date information. Sorry, you will have to do the legwork yourself. Go to
the library catalogue & the Web & search on such topics as "plant evolution &
climate."
The key to the evolution of carnivorous plants is the scarcity of nitrogen in
bog environments. Start with that & see where it leads you.
And don't forget, now that spring is coming, to get out in the woods and
actually look at plants. You will learn much more than just studying books.


Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)