I recently got a copy of the book Guide to Wild Foods and Useful Plants by Christopher Nyerges. It's the second edition, which I assume means there was a first edition out some time ago and this one has newly revised content.
As you'll read below, I've got a few critiques of this book but I like it overall. My satisfaction with it is, in part, because there are just so few books I've found AT ALL on wild edibles that are local to me. Most of what I've learned about using plants comes either from Native Americans or from books on herbal medicine. I love herbal medicine, but it's a different topic from foraging for food, which is the main focus of this book. Therefore, I think this book fills a niche that really needed to be filled.
Although I don't think it's explicitly stated (maybe it does and I missed it), the book strikes me as focusing on plants found in California. That includes many widespread plants found in the rest of the country too (plantain, purslane, lambs quarters, etc), but some of the plants strike me as very California (golden chia, toyon, California bay, manzanita). Therefore, if you're trying to learn how to forage for your dinner in California, this is a good book for you. If you live somewhere else, there will be some entries in here that might not be helpful to you, and the book might neglect to mention plants that are local to you like Oregon grape.
All in all, the book does a few things I like a lot. First, it has an appendix called "Safe Families" in which it lets you know which plant families are entirely safe to eat. Maybe some plants in a safe family don't taste good, but at least you won't die eating them. Hallelujah.
Second, the book also identifies poisonous plants - poison hemlock, poison oak, tree tobacco, jimsonweed a.k.a. datura. Again, hallelujah. One of the most important things to know when you start foraging is which poisonous plants are out there. I know that when I find a plant I think is probably miner's lettuce, I can probably eat it without worrying, but if I think I've found a wild carrot, I should be wary because it looks a lot like poison hemlock.
A third feature I like is the glossary. I'm willing to bet that most aspiring foragers are not up on all of the botanical terms out there (peduncle, pinnate, palmate, etc). The author takes pity on readers by providing a fantastic glossary with drawings.
I'm also generally happy with the plants the author chose to focus on. Many are very common and easy to find and identify. Strangely, he chose to leave out a few big, obvious ones in my view (mesquite, blackberries, and grapes, for example). But he's got most of the important ones included - cattails, a lot of edible greens, currants and gooseberries, acorns, passionflower, nasturtium, mustard, etc.
The book has photos, although I do not know if the photos are good enough to help a newbie actually identify a plant well enough to feel comfortable eating it. That's not a critique of the photos, it's just that I already know how to identify most of the plants so I'm not actually using the photos in that way myself. I think drawings of the plants might be a good addition to help make it more clear to readers how to identify them. This is just something that's really tricky for any guide book on this subject.
So is explaining to readers where any particular plant is found. A broad explanation like "found throughout the Southwest" does little to let a reader know if the plant is found exactly where they live, but too narrow of an explanation, like a list of counties where the plant is present, would be ridiculously long for any guide book. I can't say I feel like this book does the best job at this, but it's a very hard thing to do. Ultimately, you're best off to get a local guide book - I use James Lightner's San Diego County Native Plants - and use that together with a book like this one. And that's exactly what I do.
I do have one real critique of the book. Some of the information is inaccurate. For example, the author gives "tule" as a possible common name for cattails. Tules are different plants. They look a lot like cattails and grow in the same places, but they are not the same plants.
I have not spotted any more confirmable errors like that, although I have raised an eyebrow more than once when reading the "common names" given for various plants. For example, he writes that mugwort (Artemisia douglasiana, not vulgaris) is sometimes called sagebrush or purple sage. I've never heard either. The plant I call sagebrush is a related plant, A. tridentata. I've also heard A. californica referred to as California sagebrush. And at least those are in the same family and genus. I've always referred to Salvia leucophylla as Purple Sage, and that's in a different family altogether. Common names can be imprecise and sometimes people refer to two different plants by the same name, so I can't say for sure that this is "wrong," but it seemed odd at the very least.
Fortunately, at least the author doesn't make mistakes that cause anyone real harm, like suggesting that poison oak is good in salad. The closest he comes to that is suggesting that mugwort can be consumed, and I've heard some people caution against that but I think other people think it's OK. I would have liked if he mentioned that it's controversial so people at least know to look up more info before putting it in their mouths.
All in all, this is a good and useful book, especially if you live in California.