Milk Mushrooms of North America: A Field Identification Guide to the Genus Lactarius
I suspect that most NAMA members have used, or at least seen, one or more of the fine mushroom books produced by Alan and Arleen Bessette such as North American Boletes, Mushrooms of Northeastern North America, Mushrooms of the Southeastern United States, Mushrooms of Cape Cod and the National Seashore, and Edible Wild Mushrooms of North America. Although most of these have unique characteristics, they share several features, such as inclusion of one or more co-authors, top-notch color photographs, fairly concise descriptions written without a lot of technical jargon, and simple, easy-to-navigate keys to the included species. Thus, it is not surprising that the long-awaited newest member of the Bessette stable is quite similar to their earlier efforts, particularly North American Boletes.
Like most Bessette books, the front matter and introductory sections are fairly brief. Here they include a definition of the genus Lactarius, principal features used to classify and identify species within the genus, ecology (all species are thought to be ectomycorrhizal), edibility (not many species are high on the lists of many mycophagists), notes concerning the descriptions, key field characters that should be noted when you collect lactariuses, and some hints for using the keys. All of this is covered in a mere 10 pages. Back sections include a glossary, list of references, separate indexes to scientific and common names, and list of photo credits.
As usual, the bulk of the book is devoted to the mushroom species descriptions. They are arranged alphabetically by species epithet, rather than taxonomically. I waffle between preferring one versus the other, so I can easily live with this approach. But still I see value in organizing by subgenus and then alphabetizing within those groups. That way similar species that one is trying to decide among would appear closer together for easier comparison. Lacking that, it would have been helpful for the descriptions to include the subgenus and section, at least as they are currently classified. But, on the other hand, as the infrageneric classification will change in response to the growing body of molecular phylogenetic studies, the straight alphabetical approach may well be the better one for avoiding becoming dated. See, I waffle.
Most of the species are typical lactariuses with stipe, cap, and normal gills, but a small selection of related secotioid, hypogeous, and polypore species is included, plus two common parasites on lactariuses - Hypomyces lactifluorum (which produces the lobster mushroom) and Asterophora lycoperdoides. Each description includes the authority and source of original description and information on cap; gills; stalk; flesh; latex; spore-color; microscopic characters such as structure of the cuticle and spore size, shape, and ornamentation; geographic, seasonal, and habitat occurrence; and edibility. Each ends with a usually brief comments section. The descriptions are fairly short and written in accessible language. My only complaint about them is that the comments sections mostly are too short. I feel this is the most important part of the description as this is where the authors can focus your attention on the most similar species and the characters you need to observe to tell this species from its lookalikes. It’s also a place to provide miscellaneous tidbits of interesting information such as why Lactarius volemus mushrooms are known as Bradleys in some parts of the country (that particular information is given in the introductory section on edibility however).
For the most part, the species included are those treated in Hesler and Smith’s 1979 monograph, North American Species of Lactarius, augmented by Andy Methven’s treatment for California (Agaricales of California, Volume 10), and the descriptions are largely based on those works. Some species considered doubtful by Hesler and Smith are not included and many of the rare or dubious (in my mind, at least) species are described, but images of them could not be found. Unfortunately, the book does not include much of the information that has come out of recent molecular studies such as the apparent lack of a clear separation between Lactarius and Russula and the possibility that the mushrooms we have been calling L. deliciosus in North America probably represent a number of different, currently un-named, species that don’t include the “real” thing. In part this is because the authors’ manuscript was submitted years ago and the publisher took an unusually long time to publish the book.
The written descriptions are supported by excellent-quality color photographs from the authors and 21 other individuals. 151 of the 220 species and varieties of Lactarius treated in the book are illustrated, an admirable 71 of them by more than one photo to show variability within the species. The photos are of generous size (about 7 x 11 cm or 2-3/4 x 4-1/2 inches) which greatly increases their utility for identification purposes. All of them are grouped together, arranged alphabetically, and placed after the keys and before the written descriptions. For me, the photos are, by far, the most valuable part of the book.
The keys are very similar to those in earlier Bessette books. As in North American Boletes, they are divided into Eastern and Western groups, with the Rocky Mountains serving as the line of division. Each geographic set is then divided into four “field groups.” Most of the couplets address only one or two characters, such as cap color, cap zonation, latex color, latex taste, and type of associated tree. Although I haven’t made much use of the keys in previous Bessette volumes, usually I have been successful on those occasions when I did use them. However, another mycologist I know simply hates the Bessettes’ keys. Perhaps the problem stems from the trade-off that is inevitable when trying to produce relatively simple keys that most folks won’t find overwhelming. The simpler a key is, the more likely it is that it won’t always work well. Conversely, a key designed to work in most instances will of necessity be more complex and possibly intimidating. I think these keys strike a good balance between the two approaches. Just be forewarned, because they are fairly simple, they won’t always work.
Small quibbles notwithstanding, this is a fine book that makes a valuable contribution to the mycological literature of North America and it should be welcomed by mushroom-hunters throughout the continent and beyond. Welcomed, that is, IF they can afford it. Those large photos come at a price—$110—ouch! It’s a real shame that Syracuse University Press chose to print the book only in hard cover. Although profit models may suggest that was the best approach for the Press, it certainly doesn’t help to get the book into the hands of a large number of mushroomers. If you can afford it, get it. If not, start saving, you won’t regret it.