Jacaranda mimosifolia I believe.

@smivies I ruled out mulberry because the results I saw all said they had berries. In my 3 years at this house I've never seen berries on the tree. Answer still stand? They are common and nothing special, no? I have ripped out a few plantings from the PO and lived to regret doing so. Due to its position I hadn't intended to take any care in digging it out but if it is worth saving I would probably try and give it away on craigslist.

Thank you all for your input and advice. And sorry for the suspense - I couldn't find the camera cord. And another apology - I said "soil", but should've said "mix": I've got them growing in metro-mix 830 (peat, composted bark, perlite, vermiculite, dolomite lime, and blue chip). Below are links to the pics of the trees as they live in their environment. I posted links rather than the pics themselves so that I could keep the images large enough to show as much detail as possible. Houstontexas123 thanks for that link. After comparing mine I would say it looks like their iron-deficient leaves look most like mine, but again, when it comes down to it, I can't say that any of them look anything like mine. After reading your generous comments above, and reading the back of the metro-mix bag (where it recommends a constant application of fertilizer after at most the third watering), and contemplating my own ignorance, I'm pretty much coming to the conclusion that my poor citrus are deficient in probably pretty much just about everything. Heh. I guess what took me so long to wake up was that it took me so long to hit bottom. My Meyer is six or seven years old now, and has been producing happily and abundantly in the same pot until only last year without aid of any more than a general granulated house plant fertilizer that I put in the water when I brought them in for the winter. : you can see the newer growth is even yellower than the old growth (you should be able to enlarge the images by clicking them if they don't automatically fill your brower). : older growth is yellowing out and dropping off. You can see a few fruit, also sadly yellowish. : newer growth yellower than old as well. I looked around the internet and town good and long for Vigoro citrus and avocado fertilizer but couldn't seem to find anyone who was selling it or could order it, so I picked up a box of Dr. Earth's Fruit Tree Fertilizer. It lists citrus as a primary use, so ought to address my flagrant nutrientlessness. It's quick-release too, so hopefully I'll see some results soon.

I just came across this thread, if you haven't found out what it is already it's a bur cucumber, sicyos angulatus. They do grow incredibly far out and I've seen them climb to the very top of trees that are atleast 80 feet tall. Leaves can be enormous also.