Informative, and yes, also exceedingly interesting, Lee Allen Peterson's A Field Guide to Edible Wild Plants: Eastern and Central North America (originally published in 1978, but my copy is the 1999 edition) is a reference guide that primarily has been conceptualised for one main purpose, and that therefore A Field Guide to Edible Wild Plants: Eastern and Central North America specifically and generally only describes and showcases the many edible wild plant species of Eastern and Central North America. And while some edible wild plants usually found mostly in Western North America are included as well in A Field Guide to Edible Wild Plants: Eastern and Central North America, this usually only happens if or when these plants also tend to sometimes occur in Eastern and Central regions (in other words, if and when there is a bit of a distribution overlap).
Now Lee Allen Peterson (who I believe is the son of Roger Tory Peterson, the renowned ornithologist and founder of the concept of the Peterson Field Guides) not only details in A Field Guide to Edible Wild Plants: Eastern and Central North America what the edible wild plant species being showcased look like, how tall they are, how to identify the plants, the amount of seeds, fruits they generally produce and the like, he also shows and describes different ways in which the plants might be prepared and consumed, warnings about plants that might be toxic and/or even potentially lethal if the wrong parts are used and/or ingested, and most essentially warnings in my opinion, about toxic look-alikes (and that this is especially imperative for plants like wild carrot, wild parsnip and company, seeing that they can easily be confused with deadly poison or water hemlock, and in fact, the author cautions in A Field Guide to Edible Wild Plants: Eastern and Central North America that beginners, that novice foragers should NOT EVEN ATTEMPT to harvest wild carrots, wild parsley, yarrow etc. due the risks of possible and yes indeed often lethal misidentification being a real threat and possibility).
Finally, with regard to the accompanying pictorials, A Field Guide to Edible Wild Plants: Eastern and Central North America features both accompanying illustrations (line drawings) of the presented edible plant species and a section of colour photographs (colour plates). And personally, while I do find the illustrations easier to visually identify than the photographed plants on the colour plates, I definitely would prefer the illustrations to have been rendered in colour, rather than simply appear as black and white, read monochrome line drawings. Furthermore, I also think that it would be both interesting and fun had Lee Allen Peterson also included his own specific and tested recipes for at least some of the featured wild plants. However, all in all, A Field Guide to Edible Wild Plants: Eastern and Central North America truly is a wonderful and much informative field guide and botanical reference manual both for budding as well as serious harvesters/foragers, as well as for individuals like myself (who will not likely ever attempt to harvest or consume these edible wild plants, but do find the presented information on plants, botany and wild harvesting interesting and readable).