Name that tree

I'm thinking of a tree with, ideally, all the following characteristics.  I'm listing the important characteristics in what I think is order of importance so even if you can't name the tree due to one or two deficiencies, I will recognize the closest match.

Grows to at least 25 feet and keeps leaves/coverage all year round in a Mediterranean climate (winter lows are around 24 Fahrenheit).  FYI, I need this tree to hide the view of a nearby house and its second story window, so I can pretend I am alone in nature.

Fits in an edible forest garden.  It should have functional purpose - food, nitrogen fixing, medicine, or something ideally beyond just looking pretty.  I recognize, of course, that to some extent "doing something" is a bit open ended.  If you'd consider a particular non-food tree as an important member of an edible forest garden (permaculture) system then let me know the tree and the reason.

Grows quickly and has a large canopy (once again, to provide privacy and as soon as possible).

Thanks.  This is my first post.  I have planted 20 fruit / nut trees and bushes so far this year and I have, at least, another ten to go.

There isn't necessarily only one right answer, of course, and I appreciate any suggestions at all. 

Hmm... 24 you say? Moringa might work well. It doesn't like frost, but is should be able to handle that. It is an incredibly fast growing tree with highly nutritious leaves.

i'm not familiar with your climate but i usually figure if you want to know what grows well near you with the attributes you are looking for..look around your neighborhood for what is already growing around you..and choose from there.

make a list of what you see thriving in your area and then study the attributes of each of them

An orange tree might have the height and would probably survive the winter okay -- they do grow in the area. 

However, I'd like to consider something more exotic and more blended into an edible forest garden area of approx 1 acre.  So, I am opening this up to suggestions.

FYI, I've generally found that going by what other people are growing is a very limiting -- and often unnecessarily limiting -- set of choice.  If I did what other people are doing in my area I would have to forego permaculture pretty much, and an edible forest garden certainly, since in the collective 'wisdom' nobody around where I live seems to think either option particularly practical.  (And I guess I should have bought a house at the height of the housing bubble, since that was what others were doing at the time).

I understand what you are saying, and there is value in your advice, I just thought it might be more worthwhile to ask the question in a permaculture group.  Can anyone think of a good nitrogen fixer, for example, that might meet the leaf/cold/height criteria?

Kirk Hutchison wrote:
Hmm... 24 you say? Moringa might work well. It doesn't like frost, but is should be able to handle that. It is an incredibly fast growing tree with highly nutritious leaves.

Thank you for this suggestion!  From wikipedia, in addition to all the other amazing characteristics, I see

"Moringa species are drought-resistant and can grow in a wide variety of poor soils, even barren ground, with soil pH between 4.5 and 9.0. Although current cultivars can withstand frost, they do not generally survive a hard freeze. They can probably be grown wherever oranges grow successfully."

So, I'd like to try.  And if this doesn't fit the problem slot, for some reason, I am thinking of a warmer/better protected area where it really ought to be able to survive.

Now...any suggestion on where I could find an appropriate cultivar?