Mallow: This is a plant you have probably seen all over the place. And all of it is edible! Through a rather labor intensive process, you can even make marshmallows from it.
Those suffering from nature paranoia are quick to say that eating wild plants is dangerous because there are some plants that look so much alike that even experts can't tell them apart and that you will eat something poisonous and DIE. Not true. There are always differentiating factors among plants. For example, let's take chickweed (edible) and scarlet pimpernel (poisonous, odds fish!) Initially, they look very much alike, maybe even identical to the untrained eye, but when you turn them over, you'll see that scarlet pimpernel has black spots on the underside of its leaves and no fine hairs, unlike chickweed which has fine hairs and no black spots.
Let me also take a moment to address the John Krakauer/Into the Wild issue. No one has done more to slander wild foods and foraging than John Krakauer. In his book Into the Wild, Krakauer relates what he calls the true story of Christopher McCandless, a disillusioned rich kid who decided to head off into the Alaska wilderness and live off the land. According to Krakauer, McCandless mistook a poisonous plant for an edible one and dies. The over dramatic drivel was made into a movie by Sean Penn which has since perpetuated the myth of dangerous foraging. It should be noted though that a) the autopsy of McCandless's body showed that he died of starvation, not poisoning, b) McCandless was not an expert forager, and c) John Krakauer is full of crap. After seeing the way he represented Mormons as dangerous, backward, benighted cultists in his book Under the Banner of Heaven, I didn't hold out much hope for an accurate picture of wild foods in Into the Wild. And unfortunately Mr. Krakauer delivered.
Finding good quality plants is easiest up in the mountains where there are fewer pollutants and toxins. Last year, Malamute, Duckling, the dogs and I all went to up to Sundance and picked some of the most delightful dandelions I have ever tasted. It's possible to find good edible weeds in urbanized areas, but you have to look for places like abandoned lots that are away from busy roads. (Unfortunately, a lot of edible plants grow off of freeways and busy roads. Don't eat them unless you are starving because they have been sucking up car exhaust for months.) Make sure the land hasn't been sprayed either. Sprayed dandelions are shriveled, shrunken, gnarled looking things. Don't eat them. They don't look appetizing anyway. The area where I live has exploded in development over the past 15 years, so it's been a challenge finding places to forage. However, I found a housing development with several vacant, unsold lots off of the road (thank you 2008 housing downturn for giving me places to forage!) The weeds are growing beautifully with no indications of spraying, so I will be heading there to forage.
It is crucial to find good information on edible plants before foraging. I highly suggest John Kallas's Edible Wild Plants as a superb place to start. If you've ever wondered how to make pizza, omelets, soup, salads and tostadas with chickweed, wild spinach, nipplewort, and curly dock, this will teach you.