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Thursday, April 13, 2017

A New Flora for the Chicago Region

On Saturday, April 8th, a fat volume of botanical and ecosystem science was introduced to Chicago Region conservationists with a symposium and reception at the Chicago Botanic Garden. In his opening speech Arnold Randall, Superintendent of the Cook County Forest Preserves, highlighted the impressive fact that authors Gerould Wilhelm and Laura Rericha had worked on the new Flora of the Chicago Region for more than 100,000 hours over 17 years.

Speaking for the Botanic Garden, Dr. Greg Mueller pointed out that Chicago region has been a leader in the development of citizen science and stewardship, and that this community has been eagerly anticipating this book.

Lead author, Dr. Gerould Wilhelm (Jerry), said that the new Flora is not another edition of “Plants of the Chicago Region.” Wilhelm had joined author Floyd Swink as junior author for the 3rd edition of that book (published by the Morton Arboretum in 1979) and for the famous 4th edition, published by the Indiana Academy of Sciences in 1994. From the beginning, Swink had sought to make botany more accessible to non-experts and to include species associations, invaluable to conservationists working to restored degraded lands. Those four editions of “Plants of …” had been a major foundation (or “the Bible”) for the region’s botanical citizen scientists and stewards.

There were 2530 plants in the 4th edition. There are 3149 in the new Flora. Some of those 619 new ones are invaders. Ten have been newly described by botanists since 1994. But most resulted from each genus being “revaluated.” For example, in the genus Rubus (raspberries and blackberries) the key in 1994 divided our plants into 13 types. The 2017 key requires us to discriminate among 43 types.  

Most of the new ones are variants of what we’ve been calling dewberry (Rubus flagelaris). Dewberries, although mostly native, can be aggressive pests. Sometimes they’re controlled by herbicide. Now stewards will want to determine if there are rare dewberries among the pests. Fuller’s dewberry? Steele’s dewberry? Wheeler’s bristly dewberry?  It may not be easy. As the new Flora comments, in an introduction to the Rubus key:
The student should not be daunted by the number of taxa in this treatment. The species delineated here are … floristically meaningful … Careful assessment of populations in the field may be quite rewarding provided fully developed primocanes and floricanes are secured … Casually collected specimens will result in frustration and possibly ungracious thoughts about the parentage of our blackberries and dewberries.

I wonder if the authors were also concerned about frustrated stewards having ungracious thoughts about the parentage of botanists.

As for “primocanes and floricanes” – the new Flora will for most people require a great deal of back and forth to the glossary. It turns out that a trip from the Rubus page 960 to Glossary pages 1313 and 1316 reveals that a primocane is a first year shoot or “cane” (which does not flower) and a floricane is a second year cane (which in season produces flowers and tasty fruits). But since these definitions apply only to the genus Rubus, couldn’t the definitions be provided on page 960? And wouldn’t the key be more accessible to non-experts if the authors avoided the arcane terms and used simply “first year canes” and “second year canes”?
The inside front cover maps the Chicago Loop area in 1833 showing prairie, wooded areas, and other features.
Twenty four pages of handsome and interesting color photos show mostly botanical and insect close-ups. 
Stewards are willing to suffer through a lot of page-turning to do better conservation. Many of us are eager to see how helpful this book will be in our work. In my own case, when gathering and planting seed, I’ve long wondered about the distinction between golden ragwort and balsam ragwort. When I used the 1994 key, they often seem to blend into each other. In the new Flora, for better or worse, golden and balsam have multiplied. Now I should worry about the closely related Crawford’s, round-leaved, false wooly, savanna, and false golden ragworts, in addition to golden and balsam. In the short run, I’ll probably continue to use the old names and cite the 1994 edition as my authority. That is acceptable scientifically, until I or someone has studied the sites in question sufficiently to move on to the new names, if they help.

A big part of this new book is zoological rather than botanical. Junior author Laura Rericha has provided long lists of animals (mostly insects) associated with the various plant species. If more people study these species, conservation should be able to benefit. For example, if a rare species of ant is present, and if monitoring shows it to be decreasing, and if that decrease can be associated with an inappropriate burn regime (too frequent, too seldom, or at the wrong season?), then remedial action can be taken. A species of ant (or pollinator, or beetle) may have an important role in an ecosystem, or not.

Rericha is working on keys that will help more people identify and study our region’s ants and bees. In the new Flora, she has provided on page 909 a key to more than forty types of oak galls – each made by a different species of wasp or fly. Wilhelm pointed out that ecosystems and species are complexly interdependent. In our bodies we have roughly the same number of human cells as we do bacterial cells, many of which are important to our health. Comparable relationships are critical for other mammals, birds, and all animals. Most plants depend utterly on various fungi, bacteria, pollinators, and other symbionts. The more we understand those relationships, the better we will be as defenders and managers of ecosystems and the planet. We have a long way to go.


  1. I would like to congratulate Mr. Wilhelm and Mrs. Rericha (Anchor). I only realized the excellent deal we all are getting on this book after you mentioned the 100,000 hours of work they have done to complete it. I look forward to obtaining it and using it.

  2. At the North American Prairie Conference in Normal IL in July 2016, I introduced the "Field Biology Species Concept". FBSC emphasizes that species with different ecology and phylogeny are the species that are meaningful to field biologists. Mohlenbrock and others have created species based on morphological differences visible with only good magnification and attention to subtle differences. If ecological differences consistently exist such differences may distinguish really different species, but until ecological or phylogenetic differnces are demonstrated, I will ignore them, ie use older texts as you suggest.
    Apomixis is the formation of progeny without sex, so that progeny are genetically the same as the parent. In such case, which include the genus Rubus, there are no evolutionary rules for recognizing species, as each clone could be called a species. In the case of apomicts as with cross-breeding species the emphasis should be on distinguishing ecological differences.