I went camping and found in some woods a patch of wild onions. They tasted fine and made a good offering to a family that invited me to their dinner for helping them figure out how to put up their tent. :)

I would think that if a person had planted those onions and thought 'hey! those were mine' they would at least be happy that they were enjoyed and shared. If not then they didn't really have the right attitude while planting in a public space. I also only took a handful and there were many left for others and to self propagate for next year.

As I remember, the area was a slight depression with a full shade canopy of trees and very little undergrowth. The onions were about the only things growing there and they were widely spaced (probably 2 feet apart). They were the type of onions that are straight, not bulbed.

For hide-ability factor I'd say that detecting food is somewhat instinctual once you have a memory of a food item. I just felt strange in that area because something seemed familiar. I had a rush of old memories and then I smelled something I recognized. I looked at the plants and eventually made the connection that I was standing in the middle of an onion patch and took a few. Had I just been moving through the area and not making a short slow walk I would have totally passed them up. It took about 3-5 minutes of standing there to realize that there were onions present.

From other experience I would say that carrots would do better on the edges of the woods or in an area of light where a tree had fallen. They are not easily recognized but are nearly invisible mixed with other plants. Beets look very natural and their recognizable food is well hidden but potatoes also fit this category.

When it comes down to it though. If a hiker detects some food they have to make some decisions. Is this food safe? Do I want it? Do I want to carry it out of here? How much can I find? How much can I carry? Is it legal to take? When I presented the washed onions that I had gathered to this nice family only the father and 2 of the children (out of the 6) actually tried them. The mother and the others seemed uneasy about eating something that came from the woods. I think animals are much much more likely to ravage your crops than people are.

I attempted some iris and some calendula in meadow near a small lake in a forest. The deer got them all within hours of planting. There is a wild iris that grows in similar places. I don't know what the difference was between my iris and the wild iris.