Along the creek and under the bridge, the yellow flags are blooming. When I planted these several decades ago, I was attracted by their beauty--a dangerous seduction. I didn't know how invasive they are, and I'm sorry now that I've given them a home. The cattails are perhaps more problematic, when it comes to multiplying and choking our little creek--but the cattails are native to this place. They were here before I came, so I don't feel as responsible. Yellow flag, in contrast, is native to Europe, Asia, and North Africa and was imported to North America in the 1700s. You can find it (unfortunately) at your local nursery, where it is sold as an ornamental.
Last week, Bill put on his cutoffs and rubber boots, waded into the creek, and spent a couple of hours pulling out both yellow flags and cattails. The flags are beautiful, but unless you can contain them, don't buy them. Better yet, don't buy them at all. Because they're so mobile (they multiply not just by rhizomes but by seed and broken parts of the plant), they can become a challenge to control. Look here for a scary demonstration of their threat and here for a discussion of their biology.
These days, we're becoming more aware of the dangers posed by invasive species. Dan Egan's frightening book, The Death and Life of the Great Lakes, gives us a very clear picture of the ecological catastrophe that's occurring in the Lakes. But it's not just there. It's everywhere. We need to pay attention and remind ourselves that we can manage this, if we will.
Reading note. A supposedly daring insight came up, disguised as a question: Dr. Cole, aren't humans the most invasive species of all? She'd fielded that one many times before, during public lectures and even in her days as a teaching assistant. 'I'm not unsympathetic to that line of thinking,' she answered, 'but even if it's true, we're also the only species in any position to do anything about it.--Joe Pitkin, Analog Science Fiction and Fact, June 2012