What went wrong with my leaf pressing?

I had to press 5 different types of leaves from my yard for part of my science project. I put newspaper, then the leaves, then a little more newspaper, then my english textbook, a dictionary, and a gallon of water. I let it sit for a week. My results:


Australian bottle tree, Australian willow, kumquat bush, and lemon tree leaves worked perfectly.


But... the ficus leaf (still got flattened and everything) is BROWN!


What happened?


I need to know ASAP so I know if I should try the ficus again or do a different type of leaf. I only have time for one more round of pressing before the project is due!


Thanks :)

What went wrong with my leaf pressing?
Ficus plants are always a problem when pressing. The main reason is that they have latex in their tissues and many of them have relatively thick leaves. Not only do they turn brown (or even black) but the leaves usually drop off the stems. There are a few ways to make good Ficus specimens but the ones I've heard of require alcohol (enough to dip the plants in) and you'd need to be able to apply dry heat to your press for a few days at least. So, if you don't HAVE to have a Ficus, use something else (weed from your lawn would be easiest).