I could put the jungle a little further south and shrink the desert on the left to a) future-proof the setting if I need to fit a different continent into the same world, and b) sort out the climate-latitude thing. Thanks for the suggestion, woodb3kmaster!

I'm taking the lazy route so far with vegetation, I thought about doing it a little like:
Click image for larger version. 

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(http://ramah-palmer.deviantart.com/a...done-437794615)

Sample:
Click image for larger version. 

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I'm not sure if this is too abstract, but I think a brush with miniature tree images would distort the sense of scale too much?