Book Review — Delmarva Lichens: An Illustrated Manual


April 2019


Erin A. Tripp

Additional Authors

Delmarva Lichens: An Illustrated Manual, by James Lendemer and Nastassja Noell, is a much-welcomed contribution that highlights the lichen and allied fungal diversity of the greater Delmarva Peninsula area. Delmarva, which is far easier than saying “the region encompassed by portions of Deleware, Maryland, and Virginia,” is admittedly among the more ecologically disturbed regions for which one might write a field guide. But this is precisely what makes this contribution so special: easy is it for the biodiversity scientist to flee the madness of industrialization, mass habitat destruction, super- urbanization, and the ever-increasing pace of the I-95 corridor for quieter mountains, better air, and might I say, less shittified habitat. Lendemer and Noell instead devoted a significant portion of a half of a decade collecting and studying this disturbed corridor in attempt to bring new awareness about more cyrptic forms of biodiversity that surround tens of millions of Americans. We need more field guides written for such densely populated areas. We need to capitalize on every opportunity to educate our neighbors. This guide helps to fulfill such an imperative necessity.

Before northeastern botanists grow angry at me (“Colorado! Easy for her to say!”), I readily concur that there are lovely portions of the Delmarva Peninsula characterized by native vegetation that remain little disturbed by urbanization. They might be harder to find and smaller in size than a comparable slice of western North Carolina, but this is again what makes such tracts so ecologically valuable and, from a humanistic perspective, special. Looks like Lendemer and Noell knew just where to find these places!

This book covers 299 species in the study region. However, I could never quite figure out what exactly were the boundaries of the region. A map clearly delimiting the area would have been helpful. The introductory pages provide extensive background on geology, landscape, human settlement, and land use histories. It was a fun natural history read and loaded with appropriate references. However, the connection between this history and the modern lichen biota was not fully conveyed.

A total of ca. 4,500 specimens from the Delmarva (deriving directly from the collections of the authors in combination with herbarium material) was reviewed for this study. The authors noted that the only major collection pertinent to the study area but not reviewed for the book was that of Oliver Crichton’s at Delaware State University’s DOV Herbarium (the size of his herbarium was not mentioned in the text). It is plausible that important material might be contained within the Crichton herbarium; however, studying nearly 5,000 collections for a biota of 300 species almost surely captures >95% of the relevant data, if not more. It is, nonetheless, worth noting that distribution maps are based almost entirely on material at the NY Herbaria rather than NY in addition to another herbarium with holdings from the Delmarva region.

The preliminary conservation rankings based on a thorough review of specimen numbers stand out as a very nice addition to this work, and further highlight its value in bringing new general public awareness to biodiversity in a largely urban corridor. That so many species (Figure 2) are known primarily or only from historical material should give pause to any resident of the area, and beyond (although narrower bins would have enabled readers to visualize how many collections per taxon were represented in bin sizes of 1, 2, or 3). However, it was not entirely clear why “pre-2000” was considered “historical” during informal conservation assessments (page 12, see “Regionally Extinct”). It seems that many other authors would have opted for an older date. The distribution maps differentiate between pre-1950s and post-1950s collections, which makes me wonder why,then, was 1950 not used as a cutoff?

Although we aren’t explicitly told, taxonomy seems to largely follow Ted Esslinger’s checklist, which is widely accepted as representing the best working list of lichens in North America. However, there were departures from Esslinger’s list, and it wasn’t made clear why, or under what contexts, these decisions were made. This could have been clarified to readers on page 63.

The checklist of species starting on page 15 represents far more work than simply jotting down the names of species encountered on herbarium labels or in other works. In addition, many months of new fieldwork, thin layer chromatography, and, in other instances molecular data, were employed to help determine and define species boundaries. Readers should be very confident in the names that are included in this checklist. I was not provided with a working draft of dichotomous keys in sufficient time to fully vet the quality or assess any errors, but the format follows others published by the authors over the years, and short perusal suggests these are similarly easy to use, succinct, and very helpful.

The species entries themselves are “floristic” in style. That is, they contain short descriptions useful for rough characterizations of species, but for the most part lack measurements (and do not include protologue and type information). The latter is of course fairly standard operating procedure in botany, lichenology, and mycology (in fact, off the top of my head, I can think of only one modern flora that actually includes type information, the magnitude of which should not be underestimated!). The salient features of each taxon are, nonetheless, conveyed, and sufficient in many cases to help the reader confirm identification of a species. Still, failure to connect a name to a type always leaves open the question of species concept, a failure which I am similarly guilty of.

Regarding content on the whole, I have only one major criticism (minor points raised above should not distract from the overall utility and high quality of this work). The name of this volume includes “An Illustrated Manual.” I found this rather puzzling considering the species entries themselves do not include figure call-outs (figures of which are in the back). Thus, there is no direct connection to a species and to its corresponding figure other than the figure captions starting on page 343, and to interpret these, you are required to know quite a bit about lichen phylogeny given they are not alphabetical. For example, Cladonia dimorphoclada is covered on page 138–139 of the main text. In this text is a figure call-out for Figure 87, the distribution map, but there is no reference or connection made to the photograph of Cladonia dimorphoclada on page 362. Unfortunately, this limits the utility of the book in that species are not a “one stop shop” for the reader, but rather the reader must consult two different portions of the text, which are not directly linked to one another, and must know something about evolutionary relationships among lichens. This criticism aside said, the figures/images themselves are generally high resolution and extremely helpful.

The decision to organize any sort of guide by phylogenetic relatedness rather than some means more tangible to the non-specialist (i.e., alphabetical) immediately limits its utility for the general public. I very rarely think this is a good decision and feel no differently in this case. I was therefore somewhat puzzled by authors’ decision to organize via phylogeny given their clear (and sincere) hope that this guide will motivate new interest (by users of field guides) in their local lichen diversity, for example, from the Preface: “Our hope is that publication of this work will prove to be a turning point for the lichens in the Mid-Atlantic Region, serving as inspiration to explore and appreciate a long-neglected component of biodiversity.” Lichenologists know the alphabet. Bankers do not know lichen classification.

Stylistically, there were only minor issues, many to most of which cannot be attributed to the authors. First, the book is quite large and some may feel unwieldly for a guide that covers “only” 300 species. The extensive white space on the margins of all species entries suggests better formatting for better transportability could have been undertaken. Second, on the inside cover, it is impossible to discern green from green (which, ordinarily, sounds like perhaps a good problem to have!). The figures contained within the introduction are all fairly low resolution (i.e., Figures 1–4).

Finally, I personally find right-justified keys very difficult to read and use: it results in numerous empty lines that otherwise were perfectly suitable as space for text (for example, see page 44: Phaeophyscia pusilloides). They are also just difficult to look at.

Despite minor concerns and simple differences in opinion or different preferences than that of the others, publication of Delmarva Lichens: An Illustrated Manual by Lendemer and Noell will undoubtedly foster interest and help build new capacity in lichen identification and ecology in the Mid-Atlantic region of eastern North America. It importantly calls attention to the significance of biodiversity that somehow persists in less than optimal-sized (patches) of native habitat, which so characterize the majority of the United States, especially east of the Mississippi, as we now know it.

— Erin A. Tripp, Department of Ecology and Evolutionary Biology and Museum of Natural History University of Colorado, Boulder, CO 80309.


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