Even though I disagree with the premise that there are “invasive” plants, I must give high praise to the revised and updated second edition of Invasive Plants by Sylvan Ramsey Kaufman and Wallace Kaufman.
Published by Stackpole Books, this heavy tome is a wonderful guide to the identification of common nonnative plants that tend to grow in disturbed areas, such as along roadways, hiking trails, fields, sidewalks, lawns, and gardens.
Filled with photographs that often show the growth habit of a plant as well as its flowers and leaves, this book makes identification particularly easy. For example, I had admired for many years a vine I’d see growing here and there along a nearby road, but I had never been able to identify it. I hadn’t ever seen flowers, which is the typical starting point for using books to make an identification of a flowering plant.
But looking through the photos in this guide, I immediately recognized the distinctive heart-shaped leaves with the very long pointed tips of a plant called Cinnamon Vine or Chinese Yam (Discorea oppositifolia), the tiny flowers of which are easily overlooked from a distance. That explained why I’d never noticed them!
Invasive Plants contains a treasure trove of information about each plant. In addition to providing the identifying characteristics of each species, the authors have included the habitat and range where each plant grows, information on how these nonnative species reached North America, and references you can look up for yet more information.
The only issue I have with this book (which is the same issue I have with the movement against so-called invasive plants in general) is its description for each plant regarding its impact upon the ecosystem and how the plant should be managed.
The write-ups suggest that particular plants, such as the Cinnamon Vine, are always a problem, no matter where they grow: “Vines quickly overgrow shrubs and small trees, blocking light to the ground. Plant species diversity declines under heavy cinnamon vine cover. Vines can grow so thickly that branches break under their weight.”
But this horror story does not necessarily play out. For example, I’ve been admiring the Cinnamon Vine along the roadway where I’ve exercised for almost 3 decades now. These plants have remained few and far between.
Although I’m sure the authors’ statements do apply in particular situations where conditions are made just right by man for the growth of Cinnamon Vine, it’s misleading to give the reader the idea that the Cinnamon Vine (or any nonnative plant) is simply going to take over wherever it starts growing.
The effect of numerous authors, extension agents, government agencies, and environmental groups recommending the use of pesticides over the past decade or so is a huge increase in the application of poisons that are far more harmful to our environment than alien plants will ever be.
The reality is that these so-called invasive plants start growing, thriving, and providing habitat where bare ground with poor soil is exposed: highway medians and most yards; polluted areas such as dredge spoil, sewage sludge, and mining tailings; and the well-trodden and compacted soil of hiking trails (in national parks and forests) and farmers’ fields (where half-ton cattle wander).
However, in some wetlands where soil profiles have been disturbed by man or weather, particular alien plant species can create immense monocultures because the environmental conditions are so ideal for their growth. Thus this is the one place where human intervention does usually need to take place.
Naturalist Marlene A. Condon is the author/photographer of The Nature-friendly Garden: Creating a Backyard Haven for Plants, Wildlife, and People (Stackpole Books; information at www.marlenecondon.com). If you have a question about plants or animals, or gardening in a nature-friendly manner, send it to [email protected] and please watch for an answer in this paper.
