Water Closet for 8-23-13 Purple Loosestrife
“Exotic invasive” plants are very much with us and long have been since the English and French came here from across the sea. Botanists guess as many as half our plant species may not be native. Many of the foreigners are as beautiful as they are prolific. Like past waves of immigrant peoples they are not always greeted kindly. Some grow in dense patches as in ghettoes that keep the natives out. As the years go by, like people they spread out across the land and mingle with members of other communities. With time and forgetfulness they’ll become natives.
Let’s consider a few that despite their beauty are much maligned by those who don’t like “exotic” or “invasive”. Oriental bittersweet (Celastrus orbiculatus) vines climb the natives and in fall explode in yellow-red-orange fruit clusters that by passers pick for door ornaments. Then there is common reed (Phragmites australis) that forms dense patches in wet areas along our roads. The blades of this magnificent grass rise over ten feet, their tassel-like florescences even higher. Ever more common Japanese knotweed (Polygonum cuspitatum) crowds disturbed areas around our towns with bamboo like stems, only softer, and in late summer bending arcs of blossoms. After the leaves and flowers have gone, dew drops drip from the slender stem’s joints. In morning light they are like necklaces of transparent pearls. Aristocratic knotweed doesn’t tolerate others in its neighborhood. As with Phragmites a walk among knotweed’s dense stalks reveal no other plants. Maybe it is their exclusiveness some people don’t like. And how about burning bush (Euonymus alatus) once brought to us by state highway departments for its brilliant fall fires of red leaves? It has escaped the roads and is now sprinkled about the land. We could go on and describe the shiny black pearl-like fruit of buckthorn (Rhamnus fragula). The list is long; we’ll end with purple loosestrife (Lithrum salicaria) our main subject, a beauty much fretted about and a frequent topic of discussion among bee keepers, Stream Teamers, and wildlife protectors.
In the late decades of the last millennium purple loosestrife reached peak populations in many wet places across North America. Its dense stands took over wetlands where well adapted native plants had long held sway. Six years ago, one standing on the Maple Street Bridge, Middleton, looking south up the Ipswich River would see a wide floodplain of pink-purple this time of year. From there, the last few summers, only small patches were seen. The other day we stood high on a former railroad bridge abutment next to Maple Street and couldn’t pick out any loosestrife. What has happened to it?
As with most biological questions we aren’t sure, but have some ideas from our observations and from what we’ve read. Wildlife people fearing loss of diverse wetland habitats found that spraying herbicides, cutting, and pulling up loosestrife were not working. The striking spikes of many small blossoms, several branches per plant reminding of menorah candle arms, may produce a couple million tiny seeds per plant, which remain viable for two or three years in the soil. Starting in the 1990s, beetles called Galerucella were brought in from the Old World as mercenaries. They have nothing against loosestrife; in fact they like to eat them. Might we compare them with Hessians during our revolution who had no hatred for American colonists; they just liked their British boss’s pound and other spoils of war. Alas, any far out comparison such as this seems to be failing. Loosestrife colonists unlike the victorious Americans are on the wane. The beetles may have weakened loosestrife to the point where other wetland species are gaining the upper leaf. Examine some plants the next time you pass. You are quite likely to find their leaves pocked with holes where chewed by the beetles.
There may be another, surely unintended, enemy of purple loosestrife. Since their return here in the 1990s the beavers have flooded many acres. The Stream Team guesses three to four hundred acres in relatively small Middleton alone. Several water loving species and perhaps purple loosestrife can’t take too much water year round. There are roughly 40 known beaver dams in Middleton’s 14 square miles that keep the low areas above them impounded. We know long periods of higher water drown red maples, swamp white oaks, river birch, swamp dogwood, and ashes. Some naturalists say it adversely affects purple loosestrife.
Last Sunday a young family, parents and three boys, and Stream Team guide paddled from Farnsworth Landing on the river off Route 114 to the Peabody Street Landing, a distance of about 6 miles, most in wide floodplain through which the river channel meanders. The boys 10, 8 and 4 were delighted by the many dragonflies, damsel flies, and sunning painted turtles. A few damsel flies rested on arms and paddles. So was their guide, yet his thoughts were often on the flanking plant populations. Less than a decade ago at this time of year a paddler would pass millions of loosestrife plants, often in dense stands. Not so today, reed canary grass, smart weed, and other plants have taken over. Only a few small clumps or single pink-purple beauties were seen. At one stretch where loosestrife once dominated, yellow-green wild rice inflorescences stood above vigorous reed canary grass (Phalaris arundinacea), a grass also listed as invasive, some of us think unjustly. Wild rice (Zinzania sp.) has also been increasing in the Ipswich River floodplain in recent years. Patches, tassels shining is the sun, now stretch for almost half a mile.
In the Water Closet these past few weeks we’ve had fresh bouquets of wild flowers that include purple loosestrife. Why people buy cut flowers when flowers abound in our backyards all summer we’ll never understand. In a jar of water some species like loosestrife stay fresh and glowing for a week or more. Gather some for decoration and study. Look closely at the tiny six pedaled florets, sometimes a hundred per spike, and you might appreciate why bees might like them even for reasons other than pollen and nectar. We lovers of diversity are not saddened by purple loosestrife’s waning populations. There was too much. However, we agree with Karlene Johnson, now a sharp old lady, brought up on a Salisbury farm on the edge of salt marsh; its meadows were once her father’s hayfields. Recently after an early morning ride around now Greenbelt owned meadows she wrote, “The sun inched up over the horizon and across the marsh lighting masses of purple and gold in an intricacy of color, design and beauty, a creation beyond the talents of mankind. Invasive or not, I love loosestrife.”