As a science writer, Curtis writes both descriptive scientific pages about Carex species and then a page for each species using the writing style of a naturalist-historian that gives us insights into the names of the species and the botanists who named them. The book has new keys developed by Curtis for field identification while a wetland delineator and consultant botanist. Unlike other books on Carex, these keys begin with the taxonomic characters of shape and size of the female flower’s seed-holding sac. This papery or leathery sac, known technically as a perigynium, encloses the seed-like achene. Carex is the only genus of the family Cyperaceae that has enclosed sacs instead of open scales. Carex has triangular stems, which separates them from the round-stemmed grasses.
What could be so different about the envelope-like sacs that could differentiate Carex into sections? The answer came to Curtis one day when she emptied out an herbarium drawer with remnant Carex sacs. “I looked at them and wondered, could I sort these out by size or shape and identify them to species on sac traits alone.” The answer was “almost.” The 7 piles of seeds on the desk led to the 8 sections of the book, because the flat sac pile included two groups in the Carex subgenus Vignea, and they separated on location of the stamens either at the tip of the spikes, or at the base.
The other sections include sacs that are plump or inflated, or the kind of beak they have. Some sacs have bent or curved beaks. Some beaks are short and straight, some are long-beaked and abrupt, instead of tapered. Surprisingly, the grouping works most of the time.
For those indecisive sac shapes, Curtis has written an additional set of special keys, based on characters other than sac descriptions. So if you can’t identify a Carex plant with the main sections of this book, then there is still hope, because there are a few plants that have narrow leaves only, or the few that have hairy leaves or sacs. One key is for Carex that have less than twelve sacs in a spike. The fourth special key has just the super sedges, those conspicuous plants with with large spikes with many sacs.
By eliminating the majority of Carex species, the identification becomes easier. But as Curtis says, “easier, not easy.” Some of the species were considered varieties of a species, but now have their own species status. They are so similar that college botany courses eliminate Carex from the study of the local flora, because they are believed to be too complex.
One charming feature of Woodland Carex is the photos taken by Curtis, often lying on the forest floor, shooting the “ants-eye view.” The macro-lens shots are remarkable, and the silhouette shots of plants in the woods give the “gestalt” that a flat herbarium specimen just can’t give the viewer. Readers will be pleased with this book in 3 ring binder because they can add pages or mounted snippet specimens of their own.
No doubt about it, Woodland Carex of the Upper Midwest is designed to be a working book, even interactive. There’s even a touch of humor, as Curtis penciled in a cartoon of herself, backing up a tree with camera in one hand, trying to get the shot.
copyright © 2014 Linda Curtis, botanist