Back to our (grass)roots: New guide aims to decode grass and rush plant families

April 3, 2019 Matt Arsenault

A passion for regional ecosystems inspires a user-friendly field guide to ecologically and economically important plant groups 


Designed as a professional-quality guide, the Grasses and Rushes of Maine bridges the gap between highly technical manuals and abridged field guides to foster understanding and appreciation of these ecologically and economically important plant families. 

We spoke with Matt Arsenault, a senior botanist and ecologist with Stantec, who produced the guide in collaboration with Glen Mittelhauser, director of the not-for-profit Maine Natural History Observatory; Don Cameron, botanist and ecologist with the Maine Natural Areas Program; and Eric Doucette, assistant professor biology at Massachusetts College of Liberal Arts.


Common wood rush is widespread throughout Maine, commonly found along forest edges, woodlands, and lawns. It is easily recognized by its dense cylindrical flower clusters, hairy stems, and early flowering period.

What inspired you to produce this guide?

Matt Arsenault: Graminoids, which include grasses, rushes, and sedges, have traditionally been considered difficult plant groups to study because there are many species across the region and their identification relies heavily on subtle characteristics. Too often, we’d encounter natural resource reports where graminoids would simply be reported as “unidentified grass” or “unknown sedge.” This, in turn, creates incomplete site inventory work. We wanted to change this by making the groups more accessible to the average field scientist.

In 2013, we started by tackling sedges through the publication of the Sedges of Maine—A Field Guide to Cyperaceae. We had great success with this publication (averaging 4.9 out of 5 starts on Amazon). Almost immediately, amateur and professional botanists and ecologists were asking us, “So when are you going to do grasses and rushes?” Within a year, we were diving into creating a complement to the sedge guide, focused on covering the graminoids of Maine.


_q_tweetable:As one of the largest plant families in the world, grasses are all around us. No other plant group has shaped human civilization as much as grasses._q_

Why is it important to understand these plant families?

Matt: As one of the largest plant families in the world, grasses are all around us. No other plant group has shaped human civilization as much as grasses. For example, corn, wheat, rice, oats, and barley are all grasses and have been economic drivers since the dawn of human civilization. Think of how many people make a living from grasses—farmers, brewers, bakers, groundskeepers, ranchers, agricultural scientists—the list goes on.

From an ecosystem perspective, grasses and rushes are found in a wide range of habitats, from coastal marshes to alpine summits—and everywhere in between. These plant families can dominate certain ecosystems (such as freshwater or tidal marshes and open fields) and are critical for soil stabilization and nutrient cycling. They also provide habitat structure and food sources for invertebrates, birds, and small mammals. There are many species within these families that are rare and are of conservation concern as they represent a unique component of our natural heritage. Identification of rare grass and rush species is the first step to ensure their conservation.

It’s also important to note that these families include many non-native invasive species that can significantly alter ecosystem structure and function such as common reed (Phragmites australis) and Japanese stilt grass (Microstegium vimineum). It’s important to be able to differentiate invasive species from similar-looking native species to avoid inadvertent damage from otherwise well-intentioned invasive species control efforts.


Knotted rush occurs sporadically throughout Maine and is associated with wet seeps, shorelines, and wet meadows with a higher soil pH. It is recognized by its nearly spherical flower clusters.


How did you and your collaborators go about compiling information?

Matt: We started by extracting technical descriptions of the species through published literature including regional floras, monographs, and taxonomic treatments. We then augmented this with our own observations from our experience with these groups. We also spent countless hours in herbaria studying collections to refine our descriptions and to better understand their statewide distribution. Glen Mittelhauser compiled a large database of key characteristics for each species, which was critical in developing technical keys for the species.

Next came imagery. Compiling over 1,000 photographs was no easy task! Don Cameron took most of the photos, which focused on the important characteristics of each species. A tremendous amount of time was spent traveling around the region to collect specimens for photographs. Our friends and colleagues also generously provided images for species that were missing from our own files.


What was most rewarding in completing this project?

Matt: I especially enjoyed having the chance to build a greater appreciation of grasses. Grasses, unlike sedges and rushes, include a significant number of non-native species in the region. Before producing this guide, I typically preferred to focus on the native and lesser common species in natural ecosystems.

Honestly, in the early days of this project, I had to motivate myself to deliberately seek out populations of introduced grasses to better understand their identification and ecology. Oftentimes, this involved spending time in weedy and very unnatural habitats—such as vacant lots, roadside edges, and old agricultural fields—not the most pristine places in the region! Over time, I began to better appreciate all grasses and the subtle intrigue of each species.


What do you hope readers will learn from this guide?

Matt: Identification of graminoids isn’t scary! Yes, identification may not be as straightforward as that of showy wildflowers, but an advanced degree in botany isn’t needed to learn these groups. The only qualifications needed are a sense of curiosity and a dash of patience and perseverance.

I hope users will come to better appreciate the importance of these groups in our natural (and unnatural) landscapes and take the time to identify an unknown species. Hopefully additional populations of rare and uncommon species will be discovered as a result of this guide, providing us a better understanding of their distribution and additional conservation opportunities.


So, what’s next?

Matt: It’s still in its infancy but we are hoping to begin a field guide to the aquatic plants of New England.


You can purchase Grasses and Rushes of Maine through the University of Maine press. Online ordering is available here.

About the Author

Matt Arsenault

Matt Arsenault is a certified ecologist and a nationally recognized botanist performing everything from ecological and botanical assessments and characterizations and natural resource inventories to wildlife population surveys and water quality monitoring. He is based in our Topsham, Maine, office.

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