There are many leaves of evil. Any action that is evil is a leaf. Any cause of evil is a branch.

Avarice

Well, presumably there are many different leaves of the umbrella tree called "evil." Perhaps, if evil is a multi-leaved tree, then it has seven base evils that branch off from the trunk. Those evils are the seven deadly sins: lust, gluttony, avarice (greed), sloth, wrath, envy, and hubris (pride.) If you then think of all evil as flowing from those sins, then a "leaf" would be a sin, theoretically, that is so small that it can give birth to no other smaller sins. Perhaps one of these leaves is a "white" lie, for instance. Perhaps an example would be that hubris causes you to be overly proud. You are a big old arrogant windbag. That might cause you to tell huge lies, even criminally fraudulent lies. But your hubris, which leads to criminal lies, might also lead to small lies, white lies. You can't get much smaller than that. It is the least bad thing you do which branches back to your big branch, hubris, and ultimately back to the trunk of ultimate evil. If you are arrogant enough to fake your resume, saying that you are a medical doctor, when you never graduated med school, this may lead to you committing criminal acts, such as surgery on unsuspecting victims. When the prosecutor calls and asks to speak with Dr. Zazzy, you say "yes." Well technically, that is a lie, a white lie, since you aren't a "doctor." But given all that you have done in the bigger evil puzzle, this should be the least of your concerns. Someone rated your question down. I thumbed it up because I had such a good time playing with it. Thanks for the intellectual stimulation!

Maybe it has something to do with sins ie gluttony, envy, greed, sloth etc Like the sin a leaf is fed by the roots yet a leaf life is short, it dies in time so too evils must be short lived

It is actually the love of money. Given that, the leaves would be a variety of manifestations of evil mnotivated by greed.

Lots of them - wars, poverty, hatred, prejudice, jealousy, violent anger...

Money itself (like guns, knives etc) is not the root of all evil ... it is simply an inanimate thing. It is the actions that are often used to procure, obtain, steal it that is the 'evil'. It is this driving desire to possess it and the use it for corrupt causes that is the problem. So it is definitely not the money (merely paper or mineral) that is evil but the very human qualities that WE often display that is the problem. Greed and obsessive love of this commodity are the greatest evils. Same could be said for gold, gems ...... etc It could also be argued that money can be used for great good and could therefore be considered a blessing!