Rosewood is quite easy to get. What is VERY hard to find is real Brazilian rosewood because they banned the cutting of it a long time ago. Prior to that, it was the wood of choice for steel string acoustic guitar backs and sides. What you see now is either NOS like the secret stash that Martin and a few other guitar makers and tonewood dealers have stashed away or reclaimed stump wood. Last time that I heard, Brazilian rosewood was like a $2500 upgrade on a Martin or Santa Cruz guitar. East Indian rosewood is what you see mostly because it is plantation grown along side tea bushes. The toughest stuff to get is "real" or Cuban mahogany. That stuff hasn't been readily available since at least the mid 50's. By the time the "golden age of electric guitars" came around in the mid 50's. Gibson and others had stopped using it. That stuff is the wood that the $1,000,000 antique Chippendale tables are made from. A huge Cuban mahogany tree in the Florida Keys got hit by lightning about a year ago anit was auctioned off. The winning bidder was the US government. The GSA bought it to use for a major interior restoration project on one of the historic buildings in Washington.
Now I get to scare folks about your "edible sap or nuts" comment. Cherry fruit is edible, but cherry wood and bark have cyanide in them. On horse farms in Kentucky, they fence cherry trees and have to make sure to police up fallen branches so the horses don't eat them.